Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
145 Cards in this Set
- Front
- Back
|
What is cell theory?
|
The cell is the basic living unit of organization for all organisms All cells come from pre-existing cells |
|
|
All cells are surrounded by what?
|
A Plasma Membrane |
|
|
All cells contain what?
|
-A semi-fluid substance within the membrane Cytoplasm Chromosomes Ribosomes |
|
|
What is cytoplasm? |
Cytosol + organelles |
|
|
What are chromosomes?
|
Tiny organelles that make proteins using instructions contained in genes
|
|
|
What is the difference between a prokaryote vs. a eukaryote
|
The location of the chromosomes
|
|
|
What is a prokaryotic cell?
|
DNA in nucleotide region, without a membrane separating it from the rest of the cells |
|
|
What is a eukaryotic cell?
|
Chromosomes in nucleus, membrane enclosed organelle |
|
|
How is a eukaryotic cell different than a prokaryotic cell?
|
Within cytoplasm is a variety of membrane-bounded organelles Specialized structures in form & function Generally bigger than prokaryotic |
|
|
What is the lower limit of a cell size?
|
-0.1 to 1.0 micron Most bacteria - 1-10 microns |
|
|
What is the upper limit of a cell size?
|
Eukaryotic cells - 10-100 microns |
|
|
What limits cell size?
|
-As the cell gets bigger its volume increases faster than its surface area --Smaller objects have greater ratio of surface area to volume |
|
|
Why are there limits to cell size?
|
Meaning metabolic requirements set upper limit |
|
|
But how do cells get bigger without dying then?
|
They become multi-cellular (cells divide) and hang out really close to each other |
|
|
What is the function of the cell membrane?
|
It is the exchange organelle Plasma membrane functions as selective barrier -Allows passage of O2, nutrients & waste |
|
|
What do organelles do?
|
Containers A site for chemical reactions Make protein Make energy Make more cells |
|
|
What dos the nucleus do?
|
|
|
|
Where does the nucleus live? |
-Double membrane Membrane fused in spots to create pores -Allows large macromolecules to pass through |
|
|
What is the function of the nucleolus?
|
-Build ribosome sub units form rRNA & proteins -Exit through nuclear pores to cytoplasm & combine to form functional ribosomes |
|
|
Where does the nucleolus live?
|
In the nucleus |
|
|
What is the function of ribosomes?
|
Protein production |
|
|
What is the structure of ribosomes?
|
2 subunits combine |
|
|
What are the different types of ribosomes?
|
Free & Bound |
|
|
Where do free ribosomes live & what is their function? |
Synthesize proteins that function in cytosol |
|
|
Where do bound ribosomes live & what is their function?
|
Synthesize proteins for export or for membranes |
|
|
What is the function of the endoplasmic reticulum?
|
Manufactures membranes Synthesis & hydrolysis of many compounds |
|
|
Where does the endoplasmic reticulum live?
|
Membrane connected to nuclear envelope & extends throughout cell |
|
|
What are the two types of endoplasmic reticulum?
|
Rough & smooth ER |
|
|
What are the functions of smooth ER?
|
Metabolic processes -Synthesizes lipids (oils, phospholipids, steroids & sex hormones) -Hydrolyze glycogen into glucose in the liver -Detoxify drugs & poisons in liver --ex. alcohol & barbiturates |
|
|
What are the functions of the membrane factory?
|
-Synthesize phospholipids (builds membranes) ER membrane expands -Buds off & transfers to other parts of the cell that needs membranes |
|
|
What are the functions of rough ER?
|
Produce proteins for export out of cell -Protein secreting cells -Packaged into transport vesicles for export |
|
|
What are the functions of the Golgi Apparatus?
|
-Think UPS shipping department Ships products in vesicles -Membrane sacs -"UPS trucks" |
|
|
What are the functions of the lysosomes?
|
Also the "clean up crew" of the cell which cleans up broken down organelles -Are fused with food vacuoles --Polymers digested into monomers --Pass to cytosol to become nutrients of cell |
|
|
Where do the lysosomes live? |
Vesicles of digestive enzymes Only live in animals |
|
|
What is the pH of lysosomal enzymes?
|
Work best at a pH of 5 |
|
|
Diseases of lysosomes are often what?
|
-Digestive enzymes not working in lysosomes -Picks up biomolecules, but can't digest one -Grows larger until disrupts cell & organ function |
|
|
How many lysosomal storage diseases are there? |
More than 40 |
|
|
💖💖CUTENESS BREAK💖💖
|
|
|
|
Mitochondria & Chloroplast similarities?
|
-Generate ATP Double membranes = 2 membranes Semi-autonomous organelles -Move, change shape, divide Internal ribosomes, DNA & enzymes |
|
|
What is the function of mitochondria?
|
Generate ATP -Breakdown of sugars, fats, & other fuels In the presence of oxygen they break down larger molecules into smaller to generate energy = catabolism Generate energy in presence of O2 = aerobic respiration |
|
|
What is catabolism?
|
Mitochondria breaking down larger molecules into smaller ones to generate energy |
|
|
What is aerobic respiration?
|
Mitochondria generating energy in the presence of O2 |
|
|
What is the structure of the mitochondria?
|
-Smooth outer membrane -Highly folded inner membrane --Cristae Fluid filled space in between -Mitochondrial matrix -Contains DNA, ribosomes, & enzymes |
|
|
What cells would have a lot of mitochondria? |
Muscle & nerve cells |
|
|
What types of cells contain mitochondria
|
they all do :) |
|
|
Where are chloroplast found?
|
Only in plant organelles
|
|
|
What are the classes of plant structures?
|
-Amyloplasts -Chromoplasts -Chloroplasts |
|
|
Where are chloroplasts found?
|
In leaves, other green structures of plants in eukaryotic algae |
|
|
What is the structure of chloroplasts?
|
-Stroma = internal fluid-filled space --DNA, ribosomes, & enzymes --Thylakoids = membranous sacs where ATP is made --Grana = stacks of thylakoids |
|
|
What are the functions of chloroplasts?
|
Generate ATP & synthesize sugars -Transform solar energy into chemical energy -Produce sugars from CO2 & H2O Semi-Autonomous -Moving, changing shape, & dividing -Can reproduce by pinching in two |
|
|
How are mitochondria & chloroplasts different?
|
Organelles not part of endomembrane system Grow & reproduce -Semi-autonomous organelles Proteins primarily from free ribosomes in cytosol & a few from their own ribosomes Own circular chromosomes -Direct synthesis of proteins produced by own internal ribosomes |
|
|
What are the functions of vacuoles & vesicles
|
Little "transfer strips" |
|
|
What are the types of vacuoles?
|
Contractile vacuoles Central vacuoles |
|
|
What is the function of food vacuoles
|
Phagocytosis, fuse with lysosomes |
|
|
What is the function of contractile vacuoles |
In freshwater protists, pump excess H2O out of cell |
|
|
What is the function of central vacuoles |
Found in many mature plant cells
|
|
|
What are the functions of vacuoles in plants?
|
Stockpiling proteins or inorganic ions Depositing metabolic byproducts Storing pigments Storing defensive compounds against herbivores Selective membranes controlling what comes in or goes out |
|
|
What are peroxisomes?
|
-Easier to transport & use as energy sources Detoxify cells Produce peroxide |
|
|
What are the elements of the cytoskeleton? |
Microtubules Microfilaments Intermediate Filaments |
|
|
What is the structure of the cytoskeleton?
|
Motility through cell locomotion (cilia flagella) Regulation by organizing structures & activities of cell |
|
|
What are the functions of the centrioles? |
Guide chromosomes in mitosis |
|
|
What are three types of fibers?
|
Microtubules Intermediate filaments |
|
|
What are microfilaments?
|
Movement like contraction, crawling, "pinching" |
|
|
What are microtubules?
|
Facilitate movement of cell and materials within the cell |
|
|
What are intermediate filaments? |
Very stable- usually not broken down |
|
|
What are centrosomes?
|
Microtubule-organizing center -can nucleate the assembly of microtubules Animal cells and most protists have centrioles -pair of organelles Plants and fungi usually lack centrioles |
|
|
What is endosymbiosis theory?
|
|
|
|
What is an Endosymbiont?
|
As a partnership evolutionary advantage for both as one supplies the energy and the other supplies raw materials and protection |
|
|
What are the four types of cell to cell interactions?
|
Anchoring junction Communicating junction Plasmodesmata |
|
|
What is a tight junction?
|
Connect the plasma membranes of adjacent cells in a sheet - no leakage |
|
|
What is an anchoring junction?
|
Mechanically attached cytoskeleton of neighboring cells (desmosomes) |
|
|
What is a communicating junction?
|
Chemical or electrical signal passes directly from one cell to an adjacent one (gap junction, plasmodesmata) |
|
|
What is plasmodesmata?
|
Occurs in plant cells Specialized openings in their cell walls Cytoplasm of adjoining cells are connected Function similar to gap junctions in animal cells |
|
|
What is diffusion?
|
|
|
|
What happens in the diffusion of two solutes?
|
Each substance diffuses down its own concentration gradient, independent of concentration gradients of other substances |
|
|
What are the types of diffusion?
|
Movement from high to low concentration Movement from low to high concentration |
|
|
What is passive transport? |
No energy needed |
|
|
What is passive transport? |
Molecules move in response to a concentration gradient Diffusion is movement of molecules form high to low concentration & will continue until the concentration is the same in all regions |
|
|
What is facilitated diffusion?
|
-channels to move specific molecules through cell membranes Move from high to low concentrations through a protein channel -passive transport -no energy needed -facilitated = with help |
|
|
What is active transport?
|
-Shape change transports solute from one side of membranes to other > protein "pump" "costs" energy Cells may need molecules to move against concentration situation need to pump against concentration protein pump requires ATM (energy) |
|
|
What are the types of endocytosis?
|
Phagocytosis Receptor-mediated endocytosis |
|
|
How does phagocytosis work?
|
Fuse with lysosome for digestion |
|
|
How does pinocytosis work?
|
Non-specific process |
|
|
How does receptor-mediated endocytosis work? |
Triggered by ligand signals |
|
|
How does exocytosis work?
|
Used in plants to export cell wall material Used in animals to secrete hormones, neurotransmitters, and digestive enzymes |
|
|
What are the different types of cell membranes? |
Proteins Nucleic acids Lipids |
|
|
What are the cellular membranes have 4 components?
|
Transmembrane proteins Interior protein network Cell surface markers |
|
|
What is the phospholipid bilayer?
|
Flexible matrix, barrier to permeability |
|
|
What is the transmembrane proteins?
|
Integral membrane proteins |
|
|
What are the interior protein network? |
Peripheral or intracellular membrane proteins |
|
|
What are cell surface markers? |
Glycoproteins & glycolipids |
|
|
What are phospholipids?
|
2 fatty acids attached to the glycerol -Nonpolar and hydrophobic Phosphate group attached to the glycerol -Polar and hydrophilic Spontaneously forms a bilayer -Fatty acids are on the inside -Phosphate groups are on both surfaces |
|
|
What are membrane proteins?
|
-Cell membrane & organelle membranes each have unique collections of proteins Peripheral proteins Integral proteins |
|
|
What are peripheral proteins?
|
Loosely bound to surface of membrane |
|
|
What are integral proteins?
|
-Nonpolar regions of the protein are embedded in the interior of the bilayer -Polar regions of the protein protrude from both sides of the bilayer |
|
|
What are membrane carbohydrates?
|
-Ability of a cell to distinguish neighboring cells from another -Important in organ & tissue development -Basis for rejection of foreign cells by immune system |
|
|
What are the various functions of membrane proteins?
|
Enzymes Cell-surface receptors Cell-surface identity markers Cell-to-cell proteins Attachments to the cytoskeleton |
|
|
What is the transmembrane domain? |
Hydrophobic amino acids arranged in a helices |
|
|
What is osmosis? |
The diffusion of water from high concentration to low concentration of water across a semi permeable membrane |
|
|
How does metabolism work? |
Forming bonds between molecules through dehydration synthesis and anabolic reactions Breaking bonds between molecules through hydrolysis and catabolic reactions |
|
|
Organisms are endergonic systems so what do we need for energy? |
Synthesis Reproduction Active transport Movement Temperature regulation |
|
|
Catabolic reactions are also known as what? |
Exergonic reactions |
|
|
Anabolic reactions are also known as what? |
Endergonic reactions |
|
|
How does energy coupling work? |
Uses exergonic reactions to fuels endergonic reactions |
|
|
What kind of reaction releases energy? |
Exergonic reactions by digesting polymers Hydrolysis = catabolism |
|
|
What kind of chemical reaction requires an input of energy? |
Endergonic reactions through building polymers Dehydration synthesis = anabolism |
|
|
What is activation energy? |
Breaking down large molecules requires an initial input of energy Activation energy Large biomolecules are stable Must absorb energy to break bonds |
|
|
The amount of energy needed to destabilize the bonds of a molecule is what? |
Activation energy |
|
|
How do you reduce activation energy? |
Catalysts Reducing the amount of energy to start a reaction |
|
|
What are the different concentrations of water when dealing with diffusion? |
Hypertonic Hypotonic Isotonic |
|
|
How do enzymes work? |
Biological catalysts Proteins (&RNA) Facilitates chemical reactions by increasing the rate of reaction without being consumed, reduce activation energy, don't change free energy released or required Required for most biological reactions Highly specific- thousands of different enzymes in cells Controls reactions |
|
|
What is a substrate? |
Reactant which binds to enzyme Enzyme-substrate complex: temporary association |
|
|
What is a product of an enzyme? |
End result of reaction |
|
|
What is sucrose in an enzyme + substrates |
Enzymes breaks down sucrose Bonds to sucrose & breaks disaccharide into fructose & glucose |
|
|
What is DNA polymerase as an enzyme substrate product? |
Enzyme builds DNA adds nucleotides to a growing DNA strand |
|
|
What is the lock and key model? |
Simplistic model of enzyme action Active site: Enzymes catalytic center Pocket or groove on surface of globular protein Substrate fits into active site |
|
|
What is the induced for model? |
3D structure of enzymes fits substrate As substrate binds, enzyme changed shape leading to a tighter fit -"conformational change" -bring chemical groups in position to catalyze reaction |
|
|
Specificity of enzymes |
Reaction specific Each enzyme is substrate-specific due to fit between active site & substrate |
|
|
What enzymes are named for reaction they catalyze? |
Sucrase breaks down sucrose Processes breaks down proteins Lipases break down lipids DNA polymerase builds DNA Pepsin breaks down proteins (polypeptides) |
|
|
What factors affect enzymes? |
Enzyme concentration Substrate concentration Temperature pH Salinity Activators Inhibitors |
|
|
What is a hypertonic solution? |
More solute, less water |
|
|
What is enzyme concentration? |
Effect on rates of enzyme activity As enzymes go up the rate of reaction goes up Reaction rate levels off, substrate becomes limiting factor, not all enzyme molecules can find substrate |
|
|
What is substrate concentration |
Effect on rate of enzyme activity As substrate goes up so does the reaction rate Reaction rate levels off all enzymes have active site engaged, enzyme is saturated, maximum rate of reaction |
|
|
How does temperature affect enzymes? |
Effect on rates of enzyme activity Optimum T -greatest number of molecular collisions -human enzymes = 35•-40•C (body temp 37C) Increase beyond optimum T Increased agitation of molecules disrupts bonds -H, ionic = weak bonds Denaturation - lose 3D shape Decrease T Molecules move slower Decrease collisions |
|
|
How does pH affect enzymes? |
Effect on rates of enzyme activity Protein shape (conformation) -attraction of charged amino acids pH changes -changes charges (add or remove H+) Disrupt bonds, disrupt 3D shape Most human enzymes = pH 6-8 Depends on localized conditions Pepsin (stomach) =pH3 Trypsin (small intestines) = pH8 |
|
|
How does salt concentration affect enzymes? |
Protein shape Salinity changes Enzymes intolerant of extreme salinity |
|
|
What are activators that affect enzymes? |
Cofactors and coenzymes |
|
|
What are cofactors? |
Compounds which help enzymes Non protein, small inorganic compound & ions Bounds in enzyme molecule |
|
|
How do coenzymes affect enzymes? |
Non protein, organic molecules -bond temporarily or permenantly to enzyme near active site Many vitamins |
|
|
What are inhibitors that affect enzymes? |
Competitive Non competitive Irreversible Feedback |
|
|
How do inhibitors affect enzymes? |
Regulation of enzyme activity Other molecules that effect enzyme activity Selective inhibition & activity |
|
|
What is a hypotonic solution? |
Less solute, more water |
|
|
What are competitive inhibitors |
Effect: inhibitor & substrate "compete" for active site Ex. Penicillin blocks enzyme that batteries use to build cell walls Overcome by increasing substrate concentration |
|
|
How do non competitive inhibitors work? |
Inhibitor binds to site other than active site Allosteric site Called allosteric inhibitors Causes enzymes to change shape Renders active site unreceptive |
|
|
How do irreversible inhibitors work? |
Inhibitors permanently bind to active site Allosteric Permanently changes shape of enzymes |
|
|
How do inhibitors and activators work? |
Regulatory molecules attach to allosteric site causing conformational (shape) change Inhibitors keeps enzyme in inactive form Activator keeps enzyme in active form |
|
|
How does feedback inhibition work? |
Regulation & coordination of production Product is used by next step in pathway Final product is inhibitor of earlier step No unnecessary accumulation of product |
|
|
How does cooperatively work? |
Substrate acts as an activator Substrate causes conformational changes in enzyme -induced fit Favors binding of substrate at 2nd site Makes enzyme more active & effective |
|
|
How does "fueling the economy" work? |
Eat high energy organic molecules (food) Break them down- catabolism (digest) Capture energy in form cell can use Need an energy currency as a way to pass energy around |
|
|
What is an isotonic solution? |
Equal parts water and solute |
|
|
When managing water balance within a cell what happens when an animal cell is immersed in an isotonic solution? |
Blood cells in blood No net movement of water across plasma membrane Water flows across membrane, at same rate in both directions Volume of cell is stable |
|
|
When managing water balance within a cell what happens when an animal cell is immersed in an hypotonic solution? |
Animal cell immersed in hypotonic solution will gain water, swell and burst Water continues to enter cell To solve problem, specialized organelle, concentration vacuole Pumps water out of cell= ATP Plant cell -turgid |
|
|
When managing water balance within a cell what happens when an animal cell is immersed in an hypertonic solution? |
Animal cells immersed in this solution will loose water, shrivel & probably die Salt water organisms are hypotonic compared to their environment They have to take up water & pump out salt Plant cells - plasmolysis = wilting |
|
|
What are aquaporins? |
Water moved rapidly into & out of cells Evidence that there were water channels |
|
|
What is osmoregulation? |
Water balance vs. habitat Freshwater- hypotonic to body fluids Water flow into cells & salt loss Saltwater- hypertonic to body fluids Water loss from cells Land- dry environment Need to conserve water May also need to conserve salt |
