Unit 1 - Molecules of Life and Cellular Organization Flashcards

Question

4 Levels of Protein Structures: Secondary

Answer 1

localized folding created by H bonds - the bonding happens between non R groups types of secondary structure folding: 1. Alpha Helix - looks like a coil in the polypeptide chain keratin = a bunch of alpha helixes strung together 2. Beta Pleated Sheets - the ends are attracted to each other and there's a fold

Answer 2

3D stage - contains secondary structural components (alpha helix and beta pleated sheets) ***interactions between R groups maintain the 3D structure ***determines the protein's overall shape and stability - wrapped in is the polypeptide backbone and the amino acids

Answer 3

chaperones = they help improper amino acids from doing wrong things - group of proteins that help other proteins fold *part of tertiary structure folding

Answer 4

some proteins need to cluster with another protein to function - all subunits have to come together to work - functional protein held together by hydrogen bonds

Answer 5

enzymes = biological catalysts - most enzymes are proteins - enzymes are selective and reusable - cell conditions need to be optimal for the enzyme to work properly catalyst = speeds up rate of chemical reaction

Answer 6

1. substrate bonds to the active site of the enzyme 2. once they bind, you have the enzyme-substrate complex - the enzyme changes shape a little to fit the substrate -- Induced Fit 3. the bond of the substrate breaks, and the products are released 4. the enzyme is now free and process can repeat

Answer 7

- enzymes work best at their optimal conditions (temperature, ph) - if the conditions change, the protein can denature (unfold)

Answer 8

hydrophobic molecules - hormones (some sterols or steroids) - some are energy storage molecules - major component of cell membranes (phospholipids)

Answer 9

- some are hormones (estrogen, cortisol) - part of membrane structure (cholesterol) 4 ring structure!!!!!

Answer 10

very hydrophobic - Cholesterol moves through the blood in a lipoprotein complex - They're inside the complex so they don't have to interact with water, and the outside is the phospholipid heads so they are fine touching water

Answer 11

take cholesterol from the liver to the body - if LDL levels are too high, = bad cholosterol - we need some LDL but not too much - LDL proteins are sticky and can make plaque which causes cardiovascular diseases

Answer 12

- picks up extra cholesterol from cells and takes it to the liver to be disposed of - "good cholesterol" - HDL cleans up after LDL

Answer 13

glycerol + 3 fatty acids = triglyceride - they have a 3 carbon backbone - fatty acids are very hydrophobic - fats store lots of energy triglyceride built: - it's built in dehydration synthesis - they attach to the glycerol Fatty Acid: - can be saturated or unsaturated - can vary in length and have diff degrees of saturation

Answer 14

- straight legs - saturated from hydrogen - max amount of hydrogen - diets high in saturated fats raise LDL cholesterol - animal fats are solid at room temp because the saturated fatty acids can pack tightly together - the membrane is more solid and not as fluid

Answer 15

- kinked tail - have double bonds - better for diet - the double bonds causes bending - makes the membrane more fluid - decrease LDL, raise HDL - plant fats are liquid at room temp. because they're loosely packed together

Answer 16

molecule that's part hydrophobic and part hydrophilic ex: phospholipid - head = hydrophilic - tail = hydrophobic

Answer 17

part of the protein is on outside of the membrane, some is inside - they transect the membrane

Answer 18

doesn't integrate into the membrane (on outside of membrane)

Answer 19

protein with a carbohydrate attached to it

Answer 20

all on the outside of the cell because they're identification tags telling us what the cell type is (tells other cells what it is) - cell to cell recognition - the green tree looking thing

Answer 21

- they can move laterally in the bilayer - they don't flip (don't go upside down) - some proteins within the bilayer, which makes it slower

Answer 22

temperature: - at low temp, the membrane will solidify so the membrane won't let the right things in and out of the cell - if temp is too high, the membrane will melt which means the cell won't work - saturated fatty acids tails are less fluid than unsaturated ex: if there's a membrane with lots of unsaturated tails, the freezing point will be lower - shorter the tails, the more fluid the membrane is - longer tails make the membrane less fluid - too much cholesterol makes the membrane less fluid at high temps - if there's a lot of proteins, the membrane will be less fluid

Answer 23

to make the membrane more fluid, you take saturated fatty acids and make them unsaturated Desaturase = enzyme that inserts a double bond into the fatty acid

Answer 24

- stuff moves down the concentration gradient (from high to low) - no proteins or energy needed what can pass thru: - small, uncharged hydrophobic molecules - gases (oxygen and carbon dioxide) - a little bit of water (slowly crosses)

Answer 25

- stuff moves down the concentration gradient - no energy needed - needs proteins *need a transmembrane protein for stuff to pass through what can pass thru: - polar molecules and ions - glucose, amino acids

Answer 26

- pore-forming transmembrane proteins - like a straw going through something - many channels are gated and they open if they get a signal to open - the signal binding to the binding site allows the protein to open for it - they're very selective channels

Answer 27

- the molecules binds to the binding site and then the protein changes shape to allow for the substance to pass thru the membrane *slower than channel proteins because it only opens to let one molecule to pass

Answer 28

passive transport of water - water moves down the concentration gradient - no energy needed - sometimes need proteins - aquaporins (proteins) are water channels that facilitate fast water movement **use osmosis when you need water to get in and out of the cell quickly

Answer 29

- moves against concentration gradient (from low to high) - need energy (ATP) three phosphates come together (3 in ATP) and one gets removed from hydrolysis - the phosphate getting removed energizes the molecule to get it to change shape ex: think of lecture where the protein changes shape when the phosphate attaches (lets the stuff thru the cell) and then once you remove the phosphate, the protein goes back to its original shape and doesn't let the stuff thru the cell

Answer 30

moves substances in and out of the cells by vesicles vesicle = membrane-bound sac

Answer 31

the process where things are brought into the cell - the plasma membrane opens 3 types: phagocytosis, pinocytosis, receptor-mediated endocytosis

Answer 32

when things are brought out of the cell - fuses with the plasma membrane and the vesicle releases the contents out of the cell

Answer 33

cell-eating - makes a vesicle around the "food" or large substance

Answer 34

cell-drinking - the cell brings in everything, uses what it needs and then recycles what it doesn't need - ions, small soluble molecules

Answer 35

the molecule binds to the receptor so the molecule, receptor, and protein get brought into the cell - a vesicle takes the receptors and takes them out of the cell - the other vesicle contains the protein and molecules - some of the molecules get broken down by the lysosome

Answer 36

all living organisms are made of cells *cells are the basic unit of life

Answer 37

- bacteria communicates with each other with a chemical language - when the bacteria grows, all of them participate in proportion to the cell # Quorum Sensing: - bacteria gets in you and communicates with you and once there's enough of them in proportion to human cell #, they attack its host *bacteria are multi lingual -- they can communicate with other bacteria species - they can count how many are in their own species and how many aren't Anti-quorum sensing: they want to make a molecule that jams into the receptor binding site so the bacteria can't attack

Answer 38

- as the cell increases in size, the time for diffusion increases a lot - as the cell size increases, there's less volume per unit of the cell *volume increases more rapidly than surface area *as the cell gets bigger it needs more stuff, but the membrane can serve its needs

Answer 39

1. cell shape - some are flat and some have folds - there's more plasma membrane if there's folds 2. Compartmentalization - organelles that are membrane-bound structures that increase the membrane a lot - organelles carry out reactions in the cell

Answer 40

- maintains the shape of the nucleus - organizes chromatin (DNA and proteins) made of proteins (Lamin A and Lamin B) ex: knockout mice missing lamin A protein - they had an irregular shape of their nucleus - altered gene expression - the muscles cells didn't work correctly *as we age, the nuclear lamina isn't as strong *progeria is a result of having defective lamin-A protein

Answer 41

Smooth ER Transport Vesicles Lysosome Golgi Apparatus Plasma Membrane Rough ER Nuclear Envelope

Answer 42

Smooth ER = no ribosomes - lipid production (sterols, phospholipids, and triglycerides (fats) Rough ER = ribosomes - protein production ex: cells that make lots of lipids have lots of smooth ER ex: cells that make lots of proteins have lots of rough ER STRUCTURE FITS FUNCTION

Answer 43

sometimes chaperones are involved in protein folding chemical modifications: 1. glycosylation = protein gets connected to the carbohydrate to become a glycoprotein 2. cleavage (cutting) - the protein can be cut apart

Answer 44

1. secreted to outside of the cell 2. plasma membrane 3. lysosome

Answer 45

digests and breaks down stuff from the cell - has hydrolytic enzymes - uses proton pumps in lysosomal membrane (helps with the PH using protons) Degradation: - uses transporters to break down products in the cytosol and be reused by other organelles

Answer 46

*not an organelle 3 types: 1. microfilament 2. microtubule 3. intermediate filament ***all involved in structural support of the cell

Answer 47

extends through the cell - in cytoplasm - long proteins made of actin - actin can attach/detach to make microfilaments (dynamic) *cell division

Answer 48

in cytoplasm - dynamic (can add or remove) *chromosome movement *vesicle transport

Answer 49

in nucleus - not dynamic *nuclear lamina is made of intermediate filaments (provides structural support for the nucleus)

Answer 50

converts energy of ATP into motion - vesicles move along microtubules to get to the Golgi ex: adding the phosphate to the transport vesicle allows the motor protein to change shape and move - when you take off the phosphate, the motor protein reverts back to its original shape

Answer 51

*not part of the endomembrane system *not part of the lysosome system they use oxidation to break down molecules - breaks down products of the reaction that we don't want uses a degrading enzyme to breakdown hydrogen peroxide into water and oxygen

Answer 52

site of cellular respiration - converts food energy into ATP - found in all eukaryotes - plants have chloroplasts and mitochondria - has genes but not enough to survive on its own - has ribosomes - they have DNA - double membrane

Answer 53

site of photosynthesis - takes solar energy and converts it to chemical energy - found in plants - double membrane - have small DNA - have some genes - has ribosomes (prokaryotic-looking)

Answer 54

Endosymbiosis = a eukaryote engulfed a prokaryote which resulted in the chloroplast and mitochondria being made evidence: - endosymbiotic relationships already exist (organism living inside another organism) - similarity between bacteria, chloroplasts, and mitochondria - m and c are similar in size to avg. bacteria cell - both have double membrane - binary fission (chloroplasts, mitochondria and prokaryotes all divide that way) - single, circular chromosome - "prokaryotic" ribosomes