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160 Cards in this Set
- Front
- Back
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What is the fundamental unit of all living things?
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The cell
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What are the two groups of cells?
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Prokaryotic and eukaryotic
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What are viruses?
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They are a unique category all their own
Are made of Protein and DNA Are not considered independent cells because they cannot live independent of host |
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What are some types of prokaryotes?
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Bacteria and cyanobacteria
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Are they unicellular or multicellular?
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They are unicellular organisms
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Do they have simple or complex structures?
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Simple structures
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Do prokaryotic cells have an outer cell membrane?
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Yes
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Do they have membrane bound organelles?
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They do not contain any membrane bound organelles
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Do they have a nucleus?
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They do not have a nucleus
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Where is their genetic material then?
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It consists of a singular circular molecule of DNA concentrated in an area of the cell called the nucleoid region
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What else may there be dealing with genetic material?
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There may be smaller rings of DNA called plasmids
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How many genes do plasmids have?
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Just a few genes
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How do plasmids replicate?
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They replicate independently of the main chromosomes
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What kinds of genes do they often contain?
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Genes that allow the prokaryote to survive adverse conditions
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Do bacteria have a cell wall?
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Yes
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Do they have a cell membrane?
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Yes
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Do they have cytoplasm?
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Yes
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Where does respiration occur for bacteria?
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In the cytoplasm
(At the cell membrane) |
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All multicellular organisms and all nonbacterial unicellular organisms are composed of what?
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Eukaryotic cells
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What is a typical eukaryotic cell bound by?
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A cell membrane and contains cytoplasm
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What does cytoplasm contain?
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Organelles
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Where is the genetic material in all this?
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The material consists of linear strands of DNA organized into chromosomes and located within a membrane-enclosed organelle called the nucleus
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What do plants have that animal cells don’t?
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They have a cell wall and chloroplasts
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What do animal cells that plant cells don’t?
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They have centrioles
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Where are centrioles located?
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In the chromosome area
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What is cytosol?
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The fluid component of the cytoplasm
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What does it consist of?
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An aqueous solution containing free proteins, nutrients, and other solutes
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What is the cytoskeleton?
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It is composed of microtubules, microfilaments, and intermediate fibers, and other accessory proteins, is also found in the cytosol
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What do these proteinaceous filaments do?
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They give the cell its shape and anchor the organelles
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What else do they do?
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They function in cell maintenance and aid in intracellular transport
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What does the cell membrane do?
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It surrounds the cell and regulates the passage of materials in both directions
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What does the cell membrane exhibit that deals with the movement of things into and out of the cell?
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It exhibits selective permeability
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What is the fluid mosaic model?
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It is the generally accepted model of what the cell membrane is.
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What does it say?
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It says that the cell membrane consists of a phospholipids bilayer with proteins embedded throughout
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What are phospholipids?
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They have a hydrophilic or polar phosphoric acid region and a hydrophobic nonpolar fatty acid region
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In a lipid bilayer, where is the hydrophilic region found?
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It is found on the exterior surfaces of the membrane
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Where are the hydrophobic regions found?
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They are found in the interior of the membrane
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Where are cholesterol molecules in this?
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They are embedded in the hydrophobic interior
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What do they do?
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They contribute to the membrane’s fluidity
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Where are proteins in this?
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They are interspaced throughout the membrane and may be partially or completely embedded in the bilayer
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What are transport proteins?
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They are membrane spanning molecules that allow certain ions and polar molecules to pass through the lipid bilayer
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What are cell adhesion molecules?
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CAMs are proteins that contribute to cell recognition and adhesion, and are particularly important during development
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What are receptors?
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They are complex proteins or glycoproteins generally imbedded in the membrane with sites that bind to specific molecules in the cell’s external environment
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What is the alternative way the receptor helps out?
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It may signal across the membrane and into the cell via a second messenger
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Is the plasma membrane readily permeable?
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Only for small nonpolar molecules such as oxygen and small polar molecules such as water
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How can small charged molecules cross?
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They are usually able to cross the plasma membranes through protein channels in the membrane
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How do larger charged molecules cross the membrane?
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They cross with the assistance of carrier proteins
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What is the nucleus?
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It controls the activities of the cell, including cell division
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What is it surrounded by?
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A nuclear membrane or envelope
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Is it double or single layered?
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It is a double membrane that maintains a nuclear environment distinct from that of the cytoplasm
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What are interspersed throughout the nuclear membrane
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Nuclear pores
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What do they do?
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They allow selective two-way exchange of materials between the nucleus and the cytoplasm
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What does the nucleus contain?
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It contains the DNA
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What is the DNA complexed with?
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Structural proteins called histones
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What do they form together?
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Together they form chromosomes
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What is the nucleolus?
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It is the dense structure in the nucleus where ribosomal RNA synthesis occurs
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What are ribosomes?
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They are sites if protein production and are synthesized by the nucleolus
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What do ribosomes consist of?
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They consist of two subunits, one large and one small
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What is each subunit composed of?
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It is composed of rRNA and proteins
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What are free ribosomes?
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They are ribosomes found in the cytoplasm
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What are bound ribosomes?
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They line the outer membrane of the endoplasmic reticulum
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What is the endoplasmic reticulum
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It is a network of membrane-enclosed spaced connected at points with the nuclear membrane
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What are ER with ribosomes lining its outer surface known as?
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They are known as rough ER
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What are ER without ribosomes known as?
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They are known as smooth ER
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What is ER involved with generally?
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Generally, ER is involved with the transport of materials throughout the cell
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What types of materials are really used by the ER?
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Materials destined to be secreted from the cell
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What is smooth ER involved in?
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They are involved with lipid synthesis and the detoxification of drugs and poisons
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What is rough ER involved in?
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It is involved in protein synthesis
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Proteins synthesized by the bound ribosomes do what?
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They cross into the cisternae of the RER
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What happens there?
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They undergo chemical modification
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What happens to them then?
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Then they cross into the smooth ER, where they are secreted into cytoplasmic vesicles and are transported to the Golgi apparatus
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What is the Golgi apparatus?
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It consists of a stack of membrane-enclosed sacs
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What does it do?
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It receives vesicles and their contents from smooth ER, modifies them through glycosylation, repackages them into vesicles, and distributes them
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What is the Golgi active in the distribution of?
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Newly synthesized materials to the cell surface
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What are secretory vesicles?
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They are produced by the Golgi, and they release their contents to the cell’s exterior by the process of exocytosis
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What are vesicles and vacuoles?
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They are membrane-bound sacs involved in the transport and storage of materials that are ingested, secreted, processed, or digested by the cell
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What are lysosomes?
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They are membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion
ph 5 |
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What do they do?
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They fuse with endocytotic vacuoles, thereby breaking down the material ingested by the cell
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What else do lysosomes do?
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They aid in renewing a cell’s own components by breaking down the old ones and releasing their molecular building blocks into the cytosol for reuse
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How can a cell commit suicide?
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It can rupture its lysosome membrane and release its hydrolytic enzymes
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What is this referred to as?
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Autolysis
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What are microbodies?
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They are membrane-bound organelles specialized as containers for metabolic reactions
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What are two important types of microbodies?
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Peroxisomes and glyoxysomes
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What do peroxisomes do?
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They contain oxidative enzymes that catalyze a class of reactions in which hydrogen peroxide is produced by the transfer of hydrogen from a substrate to oxygen.
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What do peroxisomes do to fats?
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They break them down into smaller molecules that can be used for fuel
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What else?
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They can be used in the liver to detoxify compounds harmful to the body, such as alcohol
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What are they used for in seedlings?
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They convert fats into sugars until it is mature enough to produce its own sugars through photosynthesi
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What are mitochondria?
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hey are the sites of aerobic respiration within the cell and hence are the suppliers of energy
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What is each mitochondrion bound by?
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They all have an outer and inner phospholipids bilayer membrane
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What does the outer membrane do?
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It is smooth and acts as a sieve, allowing molecules through on the basis of size
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What is the area between the inner and outer membrane known as?
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It is known as the intermembrane space
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What does the inner membrane have inside it?
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It has many convolutions called cristae and a high protein content that includes the proteins of the electron transport chain
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What is the area bounded by the inner membrane?
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It is known as the mitochondrial matrix
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What is the site of?
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It is the site of many of the reactions in cell respiration
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How are mitochondria different from other organelles
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They are semiautonomous, which means they contain their own DNA which is circular and ribosomes
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What does this enable them to do?
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This enables them to self-replicate by binary fission and produce some of their own proteins
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What were mitochondria believed to be a long time ago?
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They were believed to have been early prokaryotic cells that evolved a symbiotic relationship with the ancestors of eukaryotic cells
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What are chloroplasts?
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They are plastid found only in algal and plant cells
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What do they contain?
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They contain chlorophyll
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What are they the site of?
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Photosynthesis
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What do chloroplasts contain, and what are they similar to?
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They contain their own DNA and ribosomes, and exhibit the same semi autonomy as mitochondria
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What is a cell wall?
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A tough outer cell wall that protects the cell from external stimuli and desiccation
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What has cell walls?
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Plant cells have a cell wall composed of cellulose
Fungi have a cell wall composed of chitin and other materials |
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What are centrioles?
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They are a specialized type of microtubule involved in spindle organization during cell division
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How many centrioles do animal cells have?
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They usually have a pair of centrioles that are oriented at right angles to each other
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Where do they lie?
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In a region called the centrosome
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Do plant cells have centrioles?
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They do not contain centrioles
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What does the cytoskeleton do?
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It gives the cell mechanical support, maintains its shape, and functions in cell motility
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What is it composed of?
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Microtubules, microfilaments, and intermediate filaments
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What are microtubules?
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They are hollow rods made up of polymerized tubulins that radiate throughout the cell
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What do they do?
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They provide support. They provide a framework for organelle movement within the cell
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What is composed of microtubules?
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Examples are centrioles, which direct the separation of chromosomes during cell division
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What are cilia and flagella?
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They are specialized arrangements of microtubules that extend from certain cells and are involved in cell motility
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What are microfilaments?
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They are solid rods of actin
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What do they do?
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They are involved in cell movement as well as support
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What uses microfilaments?
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Muscle contraction does
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What else do microfilaments do?
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They move materials across the plasma membrane, and in amoeboid movement
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What are intermediate filaments?
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They are a collection of fibers involved in maintenance of cytoskeletal integrity
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How thick are they?
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Their diameters fall between those of microtubules and microfilaments
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What is simple diffusion?
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It is the net movement of dissolved particles down their concentration gradients
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Which direction does it go?
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From a region of higher concentration to a region of lower concentration
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Is this an active or passive process?
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It is a passive process
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What is osmosis?
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It is the simple diffusion of water from a region of lower solute concentration to a region of higher solute concentration
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What happens when the cytoplasm of the cell has a lower solute concentration than that of the extracellular medium?
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The medium is said to be hypertonic to the cell and water will flow out, causing the cell to shrink
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What happens when the cytoplasm of a cell has a higher solute concentration than the extracellular medium?
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The medium is said to be hypotonic to the cell and water will flow in
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What does this cause the cell to do?
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It causes it to swell
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What happens if too much water flows in?
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It causes it to lyse
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What is it called when the solute concentrations inside and outside the cell are equal?
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The cell and medium are said to be isotonic
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What is facilitated diffusion?
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It is the passive transport of dissolved particles down their concentration gradient with the help of carrier molecules
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Does it require energy?
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No
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What is active transport?
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It is the net movement of dissolved particles against their concentration gradient with the help of transport proteins
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Does this require energy?
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Yes
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What is active transport needed for?
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It is required to maintain membrane potentials in specialized cells such as neurons
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What is endocytosis?
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It is a process in which the cell membrane invaginates
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What does this form?
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It forms a vesicle that contain extracellular medium
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What is pinocytosis?
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It is the ingestion of fluids or small particles
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What is phagocytosis?
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It is the engulfing of large particles
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What is exocytosis?
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In exocytosis, a vesicle within the cell fuses with the cell membrane and releases its contents to the outside
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What is an important thing to note about these two things pertaining to the membrane?
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In neither of these does the transported material actually cross the membrane
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What are the four types of tissue?
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Epithelial, connective, nervous, and muscle
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What is epithelial tissue?
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It covers the surfaces of the body and lines the cavities, protecting them against injury, invasion, and desiccation
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What is epithelium involved with?
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Absorption, secretion, and sensation
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What is connective tissue?
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It is involved with body support and other functions
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What are some specialized connective tissues?
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Answer
Side 3 Edit What is the fundamental unit of all living things? The cell Edit When was the cell discovered or studied in detail? In the 17th century Edit Why did it occur then? Because of the invention of the microscope Edit What is the Cell Theory? It is the unifying theory of what a cell is Edit What are the four parts of the Cell Theory? All living things are composed of cells. The cell is the basic functional unit of life. Cells arise only from pre-existing cells. Cells carry genetic information in the form of DNA. This genetic material is passed from parent cell to daughter cell Edit What are three tools available to study the cell and its structures? Microscopy, autoradiography, and centrifugation Edit What is the most basic tool that scientists use? The microscope Edit What is magnification? An increase in apparent size of an object Edit What is resolution? The differentiation of two closely situated objects Edit What is a compound light microscope? It is one that uses two lenses or lens systems to magnify an object Edit What is the total magnification equal to? It is equal to the product of the eyepiece magnification (usually 10x) and the magnification of the selected objective lens (usually 4x, 10x, 20x, or 100x) Edit What are the 3 chief components of the microscope? The diaphragm, the course adjustment knob, and the fine adjustment knob Edit What does the diaphragm do? It controls the amount of light passing through the specimen Edit What does the course adjustment knob do? It roughly focuses the image Edit What does the fine adjustment knob do? It sharply focuses the image Edit What is the compound light microscope generally used to observe? Nonliving specimens Edit What does light microscopy require that results in cell death? It requires contrast between cells and cell structures Edit How is this contrast obtained? Through staining techniques Edit What is an example of this? The dye hematoxylin reveals the distribution of DNA and RNA within a cell due to its affinity for negatively charged molecules Edit What is a phase contrast microscope? It is a special type of light microscope that permits the study of living cells Edit What is used to produce the contrast between cellular structures? Differences in refractive index Edit What benefit does this provide to the scientist? It does not kill the specimen Edit How does an electron microscope work? It uses a beam of electrons to allow a thousand fold higher magnification than is possible with light microscopy Edit Why is the examination of living specimens not possible with electron microscopy? Tissues must be fixed and sectioned, and sometimes stained with solutions of heavy metals Edit What is autoradiography? It is a technique that uses radioactive molecules to trace and identify cell structures and biochemical activity Edit How does this work? Cells are exposed to a radioactive compound for a brief, measured period of time Edit Then what happens to the cells? They are incubated, fixed at various intervals and processed for microscopy Edit What is each preparation covered with? A film of photographic emulsion Edit What are environmental requirements for autoradiography? The preparations must be kept in the dark for several days while the radioactive compound decays Edit What happens then? The emulsion is developed; dark silver grains reveal the distribution of radioactivity within the specimen Edit What can autoradiography be used for? It can be used to study protein synthesis; labeling amino acids with radioactive isotopes allows the pathways of protein synthesis to be examined Edit What is differential centrifugation? It is the type used to separate cells or mixtures of cells without destroying them in the process Edit What happens to them at lower speeds? The mixtures separate into layers on the basis of cell type Edit What do spinning fragmented cells at high speeds do? It causes their components to sediment at different levels in the test tube based upon their respective densities Edit What happens to ribosomes when this occurs? They go to the bottom of the test tube Edit What happens to mitochondria? They go to the top Edit What happens to lysosomes? They go to the top Edit What are the two groups of cells? Prokaryotic and eukaryotic Edit What are viruses? They are a unique category all their own Edit Are they considered cells? No Edit Why not? They are not capable of living independently Edit What are some types of prokaryotes? Bacteria and cyanobacteria Edit Are they unicellular or multicellular? They are unicellular organisms Edit Do they have simple or complex structures? Simple structures Edit Do prokaryotic cells have an outer cell membrane? Yes Edit Do they have membrane bound organelles? They do not contain any membrane bound organelles Edit Do they have a nucleus? They do not have a nucleus Edit Where is their genetic material then? It consists of a singular circular molecule of DNA concentrated in an area of the cell called the nucleoid region Edit What else may there be dealing with genetic material? There may be smaller rings of DNA called plasmids Edit How many genes do plasmids have? Just a few genes Edit How do plasmids replicate? They replicate independently of the main chromosomes Edit What kinds of genes do they often contain? Genes that allow the prokaryote to survive adverse conditions Edit Do bacteria have a cell wall? Yes Edit Do they have a cell membrane? Yes Edit Do they have cytoplasm? Yes Edit Where does respiration occur for bacteria? At the cell membrane Edit All multicellular organisms and all nonbacterial unicellular organisms are composed of what? Eukaryotic cells Edit What is a typical eukaryotic cell bound by? A cell membrane and contains cytoplasm Edit What does cytoplasm contain? Organelles Edit What are organelles suspended in? A semi fluid medium called the cytosol Edit Where is the genetic material in all this? The material consists of linear strands of DNA organized into chromosomes and located within a membrane-enclosed organelle called the nucleus Edit What do plants have that animal cells don’t? They have a cell wall and chloroplasts Edit What do animal cells that plant cells don’t? They have centrioles Edit Where are centrioles located? In the chromosome area Edit What is cytosol? The fluid component of the cytoplasm Edit What does it consist of? An aqueous solution containing free proteins, nutrients, and other solutes Edit What is the cytoskeleton? It is composed of microtubules, microfilaments, and intermediate fibers, and other accessory proteins, is also found in the cytosol Edit What do these proteinaceous filaments do? They give the cell its shape and anchor the organelles Edit What else do they do? They function in cell maintenance and aid in intracellular transport Edit What does the cell membrane do? It surrounds the cell and regulates the passage of materials in both directions Edit What does the cell membrane exhibit that deals with the movement of things into and out of the cell? It exhibits selective permeability Edit What is the fluid mosaic model? It is the generally accepted model of what the cell membrane is. Edit What does it say? It says that the cell membrane consists of a phospholipids bilayer with proteins embedded throughout Edit What are phospholipids? They have a hydrophilic or polar phosphoric acid region and a hydrophobic nonpolar fatty acid region Edit In a lipid bilayer, where is the hydrophilic region found? It is found on the exterior surfaces of the membrane Edit Where are the hydrophobic regions found? They are found in the interior of the membrane Edit Where are cholesterol molecules in this? They are embedded in the hydrophobic interior Edit What do they do? They contribute to the membrane’s fluidity Edit Where are proteins in this? They are interspaced throughout the membrane and may be partially or completely embedded in the bilayer Edit What are transport proteins? They are membrane spanning molecules that allow certain ions and polar molecules to pass through the lipid bilayer Edit What are cell adhesion molecules? CAMs are proteins that contribute to cell recognition and adhesion, and are particularly important during development Edit What are receptors? They are complex proteins or glycoproteins generally imbedded in the membrane with sites that bind to specific molecules in the cell’s external environment Edit What is pinocytosis? It is how the cell may carry the molecule into the cell Edit What is the alternative way the receptor helps out? It may signal across the membrane and into the cell via a second messenger Edit Is the plasma membrane readily permeable? Yes Edit What can go through? Small nonpolar molecules such as oxygen and small polar molecules such as water Edit How can small charged molecules cross? They are usually able to cross the plasma membranes through protein channels in the membrane Edit How do larger charged molecules cross the membrane? They cross with the assistance of carrier proteins Edit What is the nucleus? It controls the activities of the cell, including cell division Edit What is it surrounded by? A nuclear membrane or envelope Edit Is it double or single layered? It is a double membrane that maintains a nuclear environment distinct from that of the cytoplasm Edit What are interspersed throughout the nuclear membrane? Nuclear pores Edit What do they do? They allow selective two-way exchange of materials between the nucleus and the cytoplasm Edit What does the nucleus contain? It contains the DNA Edit What is the DNA complexed with? Structural proteins called histones Edit What do they form together? Together they form chromosomes Edit What is the nucleolus? It is the dense structure in the nucleus where ribosomal RNA synthesis occurs Edit What are ribosomes? They are sites if protein production and are synthesized by the nucleolus Edit What do ribosomes consist of? They consist of two subunits, one large and one small Edit What is each subunit composed of? It is composed of rRNA and proteins Edit What are free ribosomes? They are ribosomes found in the cytoplasm Edit What are bound ribosomes? They line the outer membrane of the endoplasmic reticulum Edit What is the endoplasmic reticulum? It is a network of membrane-enclosed spaced connected at points with the nuclear membrane Edit What are ER with ribosomes lining its outer surface known as? They are known as rough ER Edit What are ER without ribosomes known as? They are known as smooth ER Edit What is ER involved with generally? Generally, ER is involved with the transport of materials throughout the cell Edit What types of materials are really used by the ER? Materials destined to be secreted from the cell Edit What is smooth ER involved in? They are involved with lipid synthesis and the detoxification of drugs and poisons Edit What is rough ER involved in? It is involved in protein synthesis Edit Proteins synthesized by the bound ribosomes do what? They cross into the cisternae of the RER Edit What happens there? They undergo chemical modification Edit What happens to them then? Then they cross into the smooth ER, where they are secreted into cytoplasmic vesicles and are transported to the Golgi apparatus Edit What is the Golgi apparatus? It consists of a stack of membrane-enclosed sacs Edit What does it do? It receives vesicles and their contents from smooth ER, modifies them through glycosylation, repackages them into vesicles, and distributes them Edit What is the Golgi active in the distribution of? Newly synthesized materials to the cell surface Edit What are secretory vesicles? They are produced by the Golgi, and they release their contents to the cell’s exterior by the process of exocytosis Edit What are vesicles and vacuoles? They are membrane-bound sacs involved in the transport and storage of materials that are ingested, secreted, processed, or digested by the cell Edit Which of the two are bigger? Vacuoles are bigger than vesicles Edit Which are more likely to be found in plant cells? Vacuoles Edit What are lysosomes? They are membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion Edit What is the effective pH level? 5 Edit What does this imply? It implies they have to be enclosed within the lysosome Edit What is the lysosome? It is an acidic environment distinct from the neutral pH of the cytosol Edit What do they do? They fuse with endocytotic vacuoles, thereby breaking down the material ingested by the cell Edit What else do lysosomes do? They aid in renewing a cell’s own components by breaking down the old ones and releasing their molecular building blocks into the cytosol for reuse Edit How can a cell commit suicide? It can rupture its lysosome membrane and release its hydrolytic enzymes Edit What is this referred to as? Autolysis Edit What are microbodies? They are membrane-bound organelles specialized as containers for metabolic reactions Edit What are two important types of microbodies? Peroxisomes and glyoxysomes Edit What do peroxisomes do? They contain oxidative enzymes that catalyze a class of reactions in which hydrogen peroxide is produced by the transfer of hydrogen from a substrate to oxygen. Edit What do peroxisomes do to fats? They break them down into smaller molecules that can be used for fuel Edit What else? They can be used in the liver to detoxify compounds harmful to the body, such as alcohol Edit What are they used for in seedlings? They convert fats into sugars until it is mature enough to produce its own sugars through photosynthesis Edit What are mitochondria? They are the sites of aerobic respiration within the cell and hence are the suppliers of energy Edit What is each mitochondrion bound by? They all have an outer and inner phospholipids bilayer membrane Edit What does the outer membrane do? It is smooth and acts as a sieve, allowing molecules through on the basis of size Edit What is the area between the inner and outer membrane known as? It is known as the intermembrane space Edit What does the inner membrane have inside it? It has many convolutions called cristae and a high protein content that includes the proteins of the electron transport chain Edit What is the area bounded by the inner membrane? It is known as the mitochondrial matrix Edit What is the site of? It is the site of many of the reactions in cell respiration Edit How are mitochondria different from other organelles? They are semiautonomous, which means they contain their own DNA which is circular and ribosomes Edit What does this enable them to do? This enables them to self-replicate by binary fission and produce some of their own proteins Edit What were mitochondria believed to be a long time ago? They were believed to have been early prokaryotic cells that evolved a symbiotic relationship with the ancestors of eukaryotic cells Edit What are chloroplasts? They are plastid found only in algal and plant cells Edit What do they contain? They contain chlorophyll Edit What are they the site of? Photosynthesis Edit What do chloroplasts contain, and what are they similar to? They contain their own DNA and ribosomes, and exhibit the same semi autonomy as mitochondria Edit What is a cell wall? A tough outer cell wall that protects the cell from external stimuli and desiccation Edit What has cell walls? Plant cells have a cell wall composed of cellulose Edit What else has them? Fungi have a cell wall composed of chitin and other materials Edit Do animals have a cell wall? No they do not Edit What are centrioles? They are a specialized type of microtubule involved in spindle organization during cell division Edit What is different about them than other organelles? They are not membrane bound Edit How many centrioles do animal cells have? They usually have a pair of centrioles that are oriented at right angles to each other Edit Where do they lie? In a region called the centrosome Edit Do plant cells have centrioles? They do not contain centrioles Edit What does the cytoskeleton do? It gives the cell mechanical support, maintains its shape, and functions in cell motility Edit What is it composed of? Microtubules, microfilaments, and intermediate filaments Edit What are microtubules? They are hollow rods made up of polymerized tubulins that radiate throughout the cell Edit What do they do? They provide support. They provide a framework for organelle movement within the cell Edit What is composed of microtubules? Examples are centrioles, which direct the separation of chromosomes during cell division Edit What are cilia and flagella? They are specialized arrangements of microtubules that extend from certain cells and are involved in cell motility Edit What are microfilaments? They are solid rods of actin Edit What do they do? They are involved in cell movement as well as support Edit What uses microfilaments? Muscle contraction does Edit What else do microfilaments do? They move materials across the plasma membrane, and in amoeboid movement Edit What are intermediate filaments? They are a collection of fibers involved in maintenance of cytoskeletal integrity Edit How thick are they? Their diameters fall between those of microtubules and microfilaments Edit What is simple diffusion? It is the net movement of dissolved particles down their concentration gradients Edit Which direction does it go? From a region of higher concentration to a region of lower concentration Edit Is this an active or passive process? It is a passive process Edit What is osmosis? It is the simple diffusion of water from a region of lower solute concentration to a region of higher solute concentration Edit What happens when the cytoplasm of the cell has a lower solute concentration than that of the extracellular medium? The medium is said to be hypertonic to the cell and water will flow out, causing the cell to shrink Edit What happens when the cytoplasm of a cell has a higher solute concentration than the extracellular medium? The medium is said to be hypotonic to the cell and water will flow in Edit What does this cause the cell to do? It causes it to swell Edit What happens if too much water flows in? It causes it to lyse Edit What is it called when the solute concentrations inside and outside the cell are equal? The cell and medium are said to be isotonic Edit What is facilitated diffusion? It is the passive transport of dissolved particles down their concentration gradient with the help of carrier molecules Edit Does it require energy? No Edit What is active transport? It is the net movement of dissolved particles against their concentration gradient with the help of transport proteins Edit Does this require energy? Yes Edit What is active transport needed for? It is required to maintain membrane potentials in specialized cells such as neurons Edit What is endocytosis? It is a process in which the cell membrane invaginates Edit What does this form? It forms a vesicle that contain extracellular medium Edit What is pinocytosis? It is the ingestion of fluids or small particles Edit What is phagocytosis? It is the engulfing of large particles Edit What is exocytosis? In exocytosis, a vesicle within the cell fuses with the cell membrane and releases its contents to the outside Edit What is an important thing to note about these two things pertaining to the membrane? In neither of these does the transported material actually cross the membrane Edit What are the four types of tissue? Epithelial, connective, nervous, and muscle Edit What is epithelial tissue? It covers the surfaces of the body and lines the cavities, protecting them against injury, invasion, and desiccation Edit What is epithelium involved with? Absorption, secretion, and sensation Edit What is connective tissue? It is involved with body support and other functions Edit What are some specialized connective tissues? Bone, cartilage, tendons, ligaments, adipose tissue, and blood |
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What is nervous tissue?
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It is composed of specialized cells called neurons that are involved with perception, processing, and storage of information concerning internal and external environments
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What is muscle tissue?
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It has great contractile capability and is involved in body movement
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What are the three types of vertebrate muscle?
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Cardiac muscle, skeletal muscle, and smooth muscle
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What are viruses?
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They are unique a cellular structures composed of a nucleic acid enclosed by a protein coat
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What are the sizes of viruses?
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They range from 20 nanometers to 300 nanometers
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How big are prokaryotes?
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1 micrometer to 10 micrometer
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How big are eukaryotic cells?
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They are 10 micrometers to 100 micrometers
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How is viral DNA?
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How is viral DNA?
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What are the four types?
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Single-stranded DNA, double-stranded DNA, single-stranded RNA, and double-stranded RNA
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What is the protein coat also known as?
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The capsid
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What is it comprised of?
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Many protein subunits and may be enclosed by a membranous envelope
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What are viruses?
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They are obligate intracellular parasites
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What does this mean?
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It means they can express their genes and reproduce only within a living host cell
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Why is that?
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Because they lack the structures necessary for independent activity and reproduction
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What are viruses called that exclusively infect bacteria?
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Bacteriophages
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Does the phage capsid enter the cell?
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No
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