midterm 1 Flashcards
what can proteins do? (7 things)
speed up chemical reactions, defence, storage, transport, cellular communication, movement, and structural support
what is an enzyme?
enzymatic proteins that regulate metabolism acting as a catalyst ( speed up chemical reactions w/out being consumed by the reaction).
what are proteins constructed from?
the same 20 amino acids linked in unbranched polymers.
what is a peptide bond?
bond between amino acids.
what is the structure of an amino acid?
organic molecule with both an amino acid group and carboxyl group.
describe the flow of genetic info (DNA->RNA->Protein)
in notes 11 steps
what are ribosomes?
complexes made up of ribosomal RNA and protein that carry out protein synthesis.
are ribosomes organelles?
No, because aren’t membrane bound.
describe selective permeability.
acts a gatekeeper, some substances are allowed through the membrane while others aren’t. chemical exchanges allow for cell to discriminate.
characteristics of cellular membranes.
lipids proteins and carbs make it up. phospholipids are most common. temp affects the fluidity. double bonds cause unsaturated hydro carbon tails to move apart making membrane more fluid.
what is a fluidity buffer for the cellular membrane?
cholesterol, high temp makes less fluid restraining the phospholipid bi layer.
define amphipathic
hydrophobic and hydrophilic (phospholipids).
what are integral proteins?
the channels that penetrate the cellular membrane to form a channel to allow certain substances through.
what are peripheral proteins?
aren’t channels are only proteins on the outside attached. attached to the matrix and cytoskeleton.
what type of channel is the transport?
one spans through the membrane selectively choosing (hydrophilic). one side is a protein shuttle changing shape to fit what’s needed, use atp, some hydrolyze.
what type of transport is enzymatic activity?
two enzymes beside one another, one gathers a substance, changes the shape and moves it to the second enzyme where it changes again and moves on.
what type is signal transduction?
binding site with a specific shape at the top of a receptor molecule, signalling molecule attaches to the receptor and moves through (chemical messenger/hormone).
what type is cell-cell recognition?
glycoprotein serves as a recognition tag to a another cell membrane protein connect. (short lived).
what type is intercellular joining?
membrane proteins of adjacent cells may connect through gap/tight junctions. (long-lasting).
what type is attachment to the cytoskeleton and ECM?
elements of the cytoskeleton none covalently bond to the membrane proteins, maintains the shape, stabilize location of certain proteins.
what are the 7 characteristics of life?
order/organization, regulation, energy processing, growth, sense/response to changes, reproduction, evolutionary adaptation.
why are cells the most basic levels of organization?
smallest unit
characteristics of prokaryotic cells.
no organelles, no nucleus to hold DNA, small, have nucleoid.
what does plasmodesmata mean?
only in plant cells (eukaryotic), cytoplasm that travels between cell walls to allow cellular communication.
what makes up a phospholipid?
lipids= fats, h20 loving head and h20 hating tails, tails are 2 fatty acids.
one main function of microvilli?
increase SA which increases absorption
endomembrane system of the nucleus?
holds most genetic info in, biggest organelle, x2 membrane, nucleus pores->mRNA->to make protein, lamina=shape, matrix=fluid (chromosomes), function= synthesize and produce mRNA which code for polypeptide chains.
endomembrane system of the smooth ER.
connected to the nuclear membrane (1 system), proteins from nucleus folded and then moved from smooth to the golgi, lipids synthesize, carbs metabolism, detox of drugs (poisons), stores Ca+2
endomembrane system of the rough ER.
connected to the nuclear membrane, polypeptide chains moved from pores of nucleus into ER, make proteins certain shapes, use vesicles to transport, polypeptide chain made into proteins, membrane factory, pancreatic cells produce…
endomembrane system of the golgi apparatus.
storage of protein, cisternae are the folds, cis face= receiving side, trans face= shipping out side, vesicles from ER come here, vesicles ship out proteins to membrane or in cell to where needed.
endomembrane system of mitochondria.
production of ATP through cellular respiration, converts energy into different types for different cells, x2 membrane, folded cristae inside for >SA, re-produce or make less for the cell.
endomembrane system for chloroplast.
colour, 3 membranes, stroma=fluid inside, synthesize fatty acids, energy for photosynthesis.
peroxisomes
removes hydrogen, produce peroxide, enzymes inside break down to make it water, small compartment in between chloroplasts.
3 structures in cytoskeleton
microtubules (biggest), microfilaments (smallest), intermediate filament (middle).
what is the cytoskeleton used for?
anchoring organelles, structure, helps move organelles, act as tracks from ER to golgi and so on.
characteristics of microtubules.
hollow rod, 25 nm, protein= tublin, cell shape, cilia and flagella, chromosomes during cell division.
what are motor proteins?
legs to walk along microtubules, need ATP to move.
what is a dyne protein?
cross-linking protein on outer microtubules (doublets) that walk creating the motions of cilia.
characteristics of microfilaments.
solid rod, 7nm, protein=actin, twisted double chain shape, maintaining changes, cell motility, middle of microvilli to retain shape, stomach and down have microvilli.
characteristics of intermediate filaments.
solid rod, 12-8 nm, coiled in cables, permanent (lamina), protein=keratin, fix organelles in place (nucleus anchor)
role of cell junctions and where are they found?
place of connection and on the cell surface
role of ECM on cell surface
mass of proteins and polysaccharides, mechanical linkage, glycoproteins & proteoglycans, fibronectin, integrins.
example of protein- protein interactions
cell internal cytoskeleton physically connected to the ECM.
what is a tight junctions?
“stitching”, stuck together not fused, fuses with adjacent cells forming a barrier to force materials through with no leakage.
what is a gap junction?
channels (connexion/monomer) that allow cytoplasmic movement between adjacent cells, hydrophilic therefore won’t let water through.
what is a desmosomes?
plugs, strong, fasten together, mass protein, intermediate filaments, in tissues that stretch,
cell wall characteristics
protection/shape, cellulose matrix, 2nd-dary wall in mature cells, middle lamella in between cells.
what is plasmodesmata?
line the call wall inside with holes (not gap junctions) that allow communication between plant cells .
what are two things that are hard to break down in plant cells?
pectin and cellulose
hydrophobic defintion?
molecules dissolve in lipid bilayer & pass through membrane. (tails)
hydrophilic definition?
molecules do not cross the membrane easily. (heads)
where do transport proteins go to
channels
what do carrier proteins do when moved through the membrane?
change shape
passive transport characteristics
substance move across membrane, diffusion (NO ATP), random movement of molecules, dynamic equilibrium.
what is dynamic equilibrium?
making each concentration gradient even, constantly moving even gradients are even.
what is passive diffusion?
one solute, moves high->low, make sure in equilibrium. 2 solutes, makes same amount of each on each side high-> low,.
what is osmosis?
dilute until equilibrium, low-> high solute concentration, diffusion over selective permeable membrane.
what is water balance?
tonicity, concentration around and in, low -> high
what is osmoregulation?
hyper/hypo-tonic environments create these osmotic problems, adapatation for life, control solute concentrations &water balance.
what is fibronectin and integrins and where are they found?
fibronectin= attach to collagen & integrins, bind through cell receptor
integrins= embedded
both found in the ECM.
peripheral proteins on the cytoplasmic surface attach to what?
cytoskeleton
peripheral proteins on the ejxtracelleur surface attach tp what?
fibres of the matrix.
what is facilitated diffusion?
channel proteins, specific molecule/ion, NO ATP, aquaporins for water, ion channels for only ions that are bigger and don’t transport water. use the 3 different channels.
what is active transport?
moves substances against concentration gradient, needs ATP, specific proteins embedded in membrane, sodium/potassium pump.
where is the sodium potassium pump located and what does it do?
active transport protein channel in membrane, moves low-> high, 3 Na+ moved out, 2 potassium moved in.
what do amoebas do?
allow to extend and engulf, microfilaments forming gel mesh or release liquid to extend out.
what is cytoplasmic streaming?
moving of nutrients to move around to all parts in cell, only in plant cells.
glycolysis inputs and outputs
input= glucose (goes through glycolysis) output= 2 pyruvate, 2 ATP, and 2 NADH.
proteins turn into amino acids for what?
enter into glycolysis, acetyl, &citric acid cycle.
what does fat do?
breaks down into glycerol enters in separate spots In glycolysis. breaks down into fatty acids that enter into acetyl/ citric acid cycle.
what do carbohydrates turn into?
sugars that only enter into glycolysis.
what gets oxidized/reduced in glucose redox reaction?
glucose molecule= oxidized. 2nd reactant (6o2)= reduced
what is given off/taken in during pyruvate oxidation
transport protein travels through, CO2 given off, 1 NADH is produced, Coenzyme A to form acetyl CoA brought in to travel into citric acid cycle
inputs and outputs of the citric acid cycle?
inputs= 2 acetyl CoA. outputs= 2 ATP, 8 NADH, 6 CO2, 2 FADH2
inputs and outputs of the citric acid cycle?
inputs= 2 acetyl CoA. outputs= 2 ATP, 8 NADH, 6 CO2, 2 FADH2
what is the name of the 3 protein enzyme that produces co2, oxidizes, and turns into the CoA.
pyruvate dehydrogenase complex.
is the citric acid cycle anaerobic or aerobic?
aerobic because it requires oxygen.
what happens to glucose at the citric acid cycle?
glucose completely broken down into H & C
