Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/69

Click to flip

69 Cards in this Set

  • Front
  • Back

What is the peer review process?

The peer review process subjects scientific research papers to independent scrutiny by other qualified scientific experts (peers) before they are made public.



Nucleus?

Contains the cell’s genetic material – the chromosomes are housed here

Cytoskeleton?

Network of fibres that organise structures and activities in the cell. Functions: Support, Adhesion, Movement, Regulation of the cell

Mitochondrion?

Similar to a bacteria cell but with two membranes so that it has more surface area and therefore can generate more energy. Function: Site of cellular respiration (powerhouse of a cell)

Golgi Apparatus

Folded membranes excretory control system (manufacturing the substance to excrete). Function: Receives many of the transport vesicles produced in the rough ER and modifies these products, manufactures certain macromolecules

Centrioles

Eukaryotic cells have two small organelles called centrioles there to help the cell when it comes time to divide. They are put to work in both the process of mitosis and the process of meiosis. You will usually find them near the nucleus but they cannot be seen when the cell is not dividing. Made of Microtubules.

Cila & Flagella

Are locomotor appendages of some cells (assist in the movement)

Chloroplasts

Is a specialised member of a family of closely related plant organelles called plastids. Contains chlorophyll. Are found in leaves and other green organs of plants and in algae

Cell Wall

Is an extracellular structure of plant cells made of cellulose fibers embedded in other polysaccharides and protein. May have multiple layers

Ribosomes

Particles of ribosomal RNA and protein, carry out protein synthesis

Smooth Endoplasmic Reticulum:

Doesn’t contain ribosomes, instead contains enzymes which can synthesis lipids, metabolite carbohydrates, store calcium and detoxify poison.

Rough Endoplasmic Reticulum:

Assembly line where ribosomes are stuck together and cell produces macromolecules using this. (it is continuous with the nuclear envelope) contains ribosomes and produces proteins and membrane which are distributed by transport vesicles.

Lysosomes

Aka- the tiny stomach, Is a membranous sac of hydrolytic enzymes and can digest all kinds of macromolecules

What is gram positive?

Have cell wall containing lots of Peptidoglycan (this traps the dye in the cytoplasm)

What is gram negative?

Have a cell wall containing less of Peptidoglycan

What part of a cell does gram staining involve?

Involving the layer between the plasma membrane and the outer membrane

What costitutes a plasma membrane?

Phospholipids, lipids & fats (saturated & unsaturated)

What determines the fluidity in the membrane at cold temperatures?

The ratio of saturated and unsaturated fatty acids determines the fluidity in the membrane at cold temperatures.

What role does cholesterol play in theplasma membrane?

Cholesterol functions as a buffer, preventing lower temperatures from inhibiting fluidity and preventing higher temperatures from increasing fluidity

What are the various functions of membrane proteins?

Transport


Enzymatic activity


Signal transduction


Cell recognition


Intracellular joining


Attachment to cytosketon or ECM

What is the transport function of a protein membrane?

Transport: Proteins that span a membrane may provide a hydrophilic channel

What is the enzymatic activity function of a protein membrane?

Enzymatic Activity: A protein built into a membrane may be an enzyme of which has a exposed active site to react with an adjacent solution.

What is the signal transduction of a protein membrane?

Signal Transduction: A memprotein may act as a signaller with a binding site the exact shape of a chemical messenger (e.g.. a hormone)

What is the intracellular joining function of a protein membrane?

Intracellular Joining: Membrane proteins of adjacent cells may hook together in various kinds of auctions, such as gap junctions or tight junctions.

What is the attachement to cytoskelton function of a protein membrane?

Attachment to Cytoskeleton (or ECM): Microfilaments or other elements of the cytoskeleton may be bonded to membrane proteins, a function that assists in maintaining the cell shape and stabilises the location of certain membrane proteins.

What is the cell recognition function of a protein membrane?

Cell Recognition: Glycoproteins (a type of membrane protein) may serve as an identification tag that is recognised by other cells.

What molecules are permeable to biological membranes?

Hydrophobic molecules are lipid soluble and can pass through the membrane rapidlyNon-polar molecules can pass through the membrane.

What are the three types of transport proteins?

Uniport


Symport


Antiport

What is an uniport type of transport protein?

Carrier a single solute across a membrane

What is an symport type of transport protein?

Translocates two different solutes simultaneously in the same direction.

What is an antiport type of transport protein?

Exchange two solutes one into the cell and one out of the cell

How a voltage is generated across a biological membrane?

j

What is osmosis?

Osmosis is the spontaneous net movement of solvent molecules through a semi-permeable membrane into a region of higher solute concentration, in the direction that tends to equalise the solute concentrations on the two sides. This is effected by the concentration gradient of dissolved substances

What is tonicity?

Ability of a solution to cause a cell to gain/lose waater this has a large impact on cells without walls

What is isotonic solution?

Concentration of solute is equal on both sides of the plasma membrane (no net movement)

What is a hypertonic solution?

A solution concentration is greater outside than inside the plasma membrane and so the cell loses water.

What is a hypeotonic solution?

The solution concentration is less on the outside of the cell than inside the cell and so the cell gains water.

What is the process of phagocytosis?

Phagocytosis is a form of endocytosis in which the cell takes in macromolecules by forming a new vesicle from the plasma membrane. Specifically in this form a phagocyte or protist will land on the surface of a cell of which has unbound phagocyte surface receptors. The receptors bind with the ligands on the phagocyte. The cell is then triggered and the process of phagocytosis begins. Once in the cell the substance is broken down through enzymes and absorbed into the cell.

What is the process fo pinocytosis?

Pinocytosis otherwise known as cell-drinking, fluid endocytosis, and bulk-phase pinocytosis, is a mode of endocytosis in which small particles are brought into the cell, forming an invagination, and then suspended within small vesicles. This form of endocytosis is used primarily in the absorption of extracellular fluids in which it engulfs already-dissolved or broken-down food

What is receptor-mediated endocytosis?

After the binding of a ligand to plasma membrane-spanning receptors, a signal is sent through the membrane, leading to membrane coating, and formation of a membrane invagination. The receptor and its ligand are then opsonized in clathrin-coated vesicles. Once opsonized, the clathrin-coated vesicle uncoats (a pre-requisite for the vesicle to fuse with other membranes) and individual vesicles fuse to form the early endosome. Since the receptor is internalized with the ligand, the system is saturable and uptake will decline until receptors are recycled to the surface.

What are the two different functions of proteins in a cell?

Channel proteins


Carrier proteins

What is channel proteins?

Provide corridor that allow a specific type of molecule ot cross the membrane

What is carrier proteins?

Undergo a subtle change in shape that translocates the solute-binding site across the membrane. This protein is required for active transport and active transport only.

How are proteins made up of invididual amino acids?

To form protein, the amino acids are linked by dehydration synthesis to form peptide bonds. The chain of amino acids is also known as a polypeptide. Some proteins contain only one polypeptide chain while others, such as hemoglobin, contain several polypeptide chains all twisted together.

What is an enzyme?

A type of protein which acts as a catalyst to bring about a specific biochemical reaction.

What the three different levels of protein structure?

Primary Structure


Secondardy Structure


Tertitary Structure


Quaternary Structure

What is the primary structure of protein?

Primary Structure: The unique sequence of amino acids in a polypeptide (it is the amino acid sequence)

What is the secondary structure of protein?

Secondary Structure: The folding/coiling of a polypeptide into a repeating configuration

What is the tertitary structure of protein?

Tertiary Structure: The overall three-dimensional shape of a polypeptide OR the way in which the secondary structures are arranged in relation to each other.

What is the quaternary structure of protein?

Quaternary Structure: The overall protein structure that results from the aggregation of two or more polypeptide subunits

What is meant by the phrase ' viruses are obligate intracellular parasites"?

The term conveys the idea that viruses must carry out their reproduction by parasitising a host cell. They cannot multiply outside a living cell, they can only replicate inside of a specific host.

What is a pathogen?

A bacterium, virus, or other microorganism that can cause disease.

Are all bacteria pathogens?

False, only some are

What is the function of ribosomes?

Carry out protein synthesis

What is cell theory?

All organisms are made up of cells and the materials produced by them.

What are three common features of cells?

1. They are bounded by a plasma membrane containing a semifluid matrix


2. Contain chromosomes (at least one)


3. Have ribosomes

What are some types of prokaryotes?

Archaea and Bacteria

How many nucleus do prokaryotes have?

One chromosome

How is binary fission relevant to cell theory?

It is the way that prokaryotes reproduce

Bacteria cells are covered by a cell wall, what is special about this?

The cell is covered by a sticky capsule consisting of a sticky layer made of polysaccharides and protein

What size are prokaryotic cells approximately?

1 - 10 µm in size (most are microscopic)

What are parts of the prokaryotic cells?

Nuceloid, Membrane, Ribosomes, Cell Wall, Outer Capsule, Pili, Flagellum

What are the three shapes of prokaryotic cells

Spheres (Cocci), Rods (Bacilli), Spirals

What organisms have eukaryotic cells?

Algae, fungi, plants and animals

What size are eukaryotic cells?

10 - 100 µm in size

What are the three main components of plant cells only?

Chloroplast, central vacuole, cell wall

What is a chloroplast?

- Is a specialised member of a family of closely related plant organelles called plastids


- Contains chlorophyll


- Are found in leaves and other green organs of plants and in algae


- Where photosynthesis takes place


- Conversion of CO2 into sugars which power the biospheres

What is the central vacuole?

Part of a plant cell it is larger than the other organelles in the cell, they can be used to contain cellular waste and to isolate materials that may be harmful to the cell.

What is the cell wall?

- Is an extracellular structure of plant cells that distinguishes them from animal cells


- Are made of cellulose fibers embedded in other polysaccharides and protein


- May have multiple layers