Ch.3 Proteins & Processes

Question 1

Proteins

Answer 1

polymer of amino acids (amino acids are the monomers)

Question 2

Polypeptides

Answer 2

chains of amino acids; min ‘ bimum of 51 amino acids required to a be a polypeptide,

Question 3

4 levels of protein structure

Answer 3

Primary Structure 1 degree: amino acid chains
Secondary structure 2 degree: amino acid chains either form pleated sheets or helices (helix); HELD TOGETHER BY HYDROGEN / BONDS
Tertiary Structure 3 degree: sheets and helices fold to form a protein;
Quaternary Structure degree 4: 2 or more polypeptide chains, associating into ONE larger molecule

Question 4

Why does protein shape matter so much?

Answer 4

shape determines overall function: specifically for destroying bacteria, needs to be the same shape as it

Question 5

Difference between RNA and DNA

Answer 5

RNA: has ribs
DNA: deoxy-ribos = missing an oxygen

Question 6

Nucleic acids

Answer 6

chains of nucleotides; monomers are nucleotides

Question 7

A C T G nucleic acids and what they bond with

Answer 7

A & T: Adenine and Thymine
C & G: Cytosin and guanine

Question 8

Uracil

Answer 8

in RNA, equivalent to thymine in DNA

Question 9

How are chains of nucleic acids held together in DNA?

Answer 9

through hydrogen bonds

Question 10

mRNA function and definition

Answer 10

messenger RNA: message that leaves nucleus
Messenger RNA molecules carry the genetic information needed to make proteins. They carry the information from the DNA in the nucleus of the cell to the cytoplasm where the proteins are made.

Question 11

Codon function and definition

Answer 11

tell cell which amino acid goes in chain to get the polypeptide chain outcome

Question 12

What is translation, where does it occur, and what does it do? What is another name for translation?

Answer 12

WHERE?-Occurs in cytoplasm of the cell
-WHAT? translates RNA to protein (translating from one ‘cellular’ language to another)
-HOW? translation is protein synthesis

Question 13

What is transcription, where does it occur, and what does it do?

Answer 13

-WHERE? occurs in nucleus
-WHAT? takes it from nucleic acid to nucleic acid (DNA TO RNA) which is the same cellular language

Question 14

What happens if the polypeptide chain doesn’t fold properly into the protein?

Answer 14

this is a mutation: won’t be folded which means it can’t fully function or it might die

Question 15

Three major groups of Lipids and properties

Answer 15

fats, phospholipids, steroids
NOT MACROMOLECULES
-All non polar: won’t dissolve in water
Hydrophobic

Question 16

What is the phospholipid bilayer of the cell membrane? (Nuclear membrane)

Answer 16

Seperates extracellular fluid from intracellular fluid: acts as a barrier
Because the extracellular fluid is essentially water, only the hydrophilic heads can be in it and the hydrophilic tails are tucked in

Question 17

Structure of the phospholipid molecule

Answer 17

two tails: hydrophobic, no polar regions
Hydrophilic head: has polar regions

Question 18

Rough Endoplasmic Reticulum

Answer 18

folded layers of membrane where proteins are FOLDED/ASSEMBLED
studded with ribosomes

Question 19

Cytosol

Answer 19

fluid in which the cell’s internal structures are suspended: intracellular fluid

Question 20

Microtubules in Neurons

Answer 20

tiny tube that transports molecules and helps give the cell its shape (part of the cytoskeleton)

Question 21

Golgi body of the neuron

Answer 21

same as Golgi apparatus
tells cells where proteins should go
Membranous structure that PACKAGES protein molecules for transport

Question 22

Lysosomes of the neuron

Answer 22

sacs containing digestive enzymes that break down wastes; if it bursts through the phospholipid membrane the cell will digest itself

Question 23

Microfilaments of the neuron

Answer 23

threadlike fibers making up much of the cell’s skeleton

Question 24

Cytoplasm

Answer 24

everything between the plasma membrane and nucleus

Question 25

Chromatim

Answer 25

untangles chromosomes?f

Question 26

Nucleolus

Answer 26

produces ribosomal subscripts

Question 27

Break down of the ER, Golgi apparatus, vesicles, and lysosomes metaphorical functions

Answer 27

ER: assembly/protein folding into vesicles Golgi: shipping and receiving, sorts/modifies proteins, directs it where it should go Vesicles: transport (sacs made of membranes) Lysosymes: recycling center of dead tissue/organelles, digestive enzymes

Question 28

What synthesizes polypeptides?

Answer 28

ribosomes

Question 29

Transcription steps 1-4

Answer 29

1: DNA UNCOILS to expose a gene, a sequence of nucleotide baes that encode a protein 2: one strand of the gene serves as a template for transcribing a molecule of mRNA 3: the mRNA leaves the nucleus and comes in contact with ribosomes in the endoplasmic reticulum 4: as a ribosome moves along the mRNA, it translates the bases into a specific amino acid chain, which forms the protein

Question 30

Exocytosis

Question 31

Difference between myelinated and unmyelinated in axon potential propagation

Answer 31

Action potential propagation along unmyelinated axons requires activation of voltage-gated sodium channels along the entire length of the axon. In sharp contrast, action potential propagation along myelinated axons requires activation of voltage-gated sodium channels only in the nodal spaces.

Question 32

types of passive transport

Answer 32

diffusion, facilitated diffusion: all don't require energy facilitated diffusion require transport proteins, move from high concentration to low concentration facilitated by carrier proteins or pores in the membran diffusion, direction of concentration gradient: This spread of particles through random motion from an area of high concentration to an area of lower concentration

Question 33

function of trans membrane proteins

Answer 33

some proteins are embedded in and span the cell; some proteins change shape when other chemicals bind to them, others change shape in response to changes in electrical charge or temperature

Question 34

channel, gated channel, pump

Answer 34

channel: opening in a protein embedded in the cell membrane that allows thew passage of ions: they have specificity for ions; certain ions have to go through certain channels to pass A leaky channel always remains open for substances and ions, whereas the gated-ion channels open in response to the specific changes in the membrane potential of the channel. Gated channel: protein embedded in a cell membrane that allows substances to pass through on some occasions but not others Pump: protein in the cell membrane that ACTIVELY transports a substance across the membrane, against its concentration gradient

Question 35

sodium potassium pump function

Answer 35

The sodium-potassium pump is a trans-membrane protein that helps establish the resting membrane potential of cells, particularly neurons. In a process that requires ATP, the pump moves three sodium ions out of the cell for every two potassium ions it brings in.

Question 36

active transport

Answer 36

requires energy, Both active transport and facilitated diffusion do use proteins to assist in transport. However, active transport works against the concentration gradient, moving substances from areas of low concentration to areas of high concentration.

Question 37

Define equilibrium

Answer 37

equilibrium, of molecules on both sides of the membrane. At equilibrium, movement of molecules does not stop. At equilibrium, there is equal movement of materials in both directions, maintaining equal concentration.

Question 38

Ligand

Answer 38

binds to receptor site to alter protein shape