POB Lectures 13-23

Question 1

What are plasmids?

Answer 1

Small ‘chromosomes’ in prokaryotic bacteria

Question 2

How do bacterial cells split?

Answer 2

Binary Fission (to make one into two daughter cells)

Question 3

Bacterial Gene Transfer

Answer 3

Horizontal (F plasmid) and vertical (down genetic tree)

Question 4

Phospholipids

Answer 4

Amphipathic - hydrophobic and hydrophilic parts

Question 5

Cell Membrane

Answer 5

Cholesterol (stops solidifying and liquefying)

Question 6

Membrane Permeability

Answer 6

Number double bonds, cholesterol in membrane,

Question 7

Membrane Proteins

Answer 7

Integral proteins (middle nonpolar - outer polar) and peripheral proteins (attached to the surface of the lipid bilayer) (used for transport, enzymes, and signal transduction)

Question 8

Tonicity

Answer 8

Hypotonic (high internal concentration, low external concentration), hypertonic (low internal concentration, high external concentration)

Question 9

Facilitated diffusion

Answer 9

Channel proteins, carrier proteins

Question 10

Types of active transport

Answer 10

Uniport (one item, one direction), Symport (two items, one direction), Antiport (two items two directions)

Question 11

What are common cell structures?

Answer 11

DNA, Ribosomes, plasma membrane, cytosol

Question 12

DNA replication

Answer 12

Starts at origin of replication - helicase splits, single stranded binding proteins prevent recoiling, topoisomerase prevents supercoiling, primase creates a primer, and DNA polymerase 1 synthesizes 5’–> 3’ New nucleotides are added onto the 3’ OH group by dehydration synthesis The lagging strand is discontinuously synthesized in okazaki fragments going in the 5’ to 3’ direction (the lagging strand comes out of the replication fork in the 5’ to 3’ direction, and they’re antiparalell strands). DNA polymerase 3 then comes in and replaces the primer with the corresponding nucleotides, and dna ligase connects the phosphodiester bonds.

Question 13

Types of transfer

Answer 13

Horizontal (transduction - from a virus) (transformation - from the environment) (conjugation - bacteria to bacteria) Vertical (down from parent –> daughter cell)

Question 14

Redox

Answer 14

Reduction - gaining an electron Oxidation - losing an electron Oxidation agent - electron acceptor (electronegative) - gains an electron Reducing agent - electron donor - loses an electron

Question 15

What is the equation for photosynthesis?

Answer 15

6CO2+6H20–>C6H12O6+6H2O

Question 16

Electron transfer

Answer 16

Less electronegative to more electronegative - exergonic

Question 17

What are the parts of photosynthesis?

Answer 17

Light reactions and the calvin cycle (light independent reactions)

Question 18

Pigments

Answer 18

Chlorophyll a, Chlorophyll b, Carotenoids

Question 19

Light reactions of photosynthesis

Answer 19

Photosystems (light harvesting complexes, reaction center) inside the thylakoid membrane - cytochrome complex between PS2 and PS1 - transfers by electron transport chain

Question 20

Photosynthesis

Answer 20

(in PS2) Photon + electron from H20 (hydrogen goes to the other side of gradient) - O2 is released - ATP created by electron transport chain to cytochrome complex (more H+ is transferred against the concentration gradient), goes to PS1, then the electron is captured in NADPH - ATP synthase uses the concentration gradient oh H+ outside the cell and turns it into ATP as the H+ gradient moves towards equilibrium

Question 21

Calvin cycle

Answer 21

Fixation (CO2 and RuBP (5 carbon sugar) –> 2 3-PG molecules Reduction Needs to be done 3 times! to create 63PG molecules so regeneration can happen Final product 1G3P (RuBP is regenerated with 5G3P) Net energy 6NADPH + 9ATP

Carbon fixation (taking carbon from CO2 and making it into a ring structure CO2+ATP+NADPH–>sugar Carbon is reduced Anabolic reaction

Question 22

Redox reaction example

Answer 22

a. A redox reaction: 6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 i. CO2 gains e- (and a proton, H) – is reduced ii. H2O loses e- (and a proton, H) – is oxidized

Question 23

How many times does the calvin cycle run?

Answer 23

3

Question 24

What are the inputs in the calvin cycle?

Answer 24

ATP and NADPH from the light-independent reactions in photosynthesis - phosphorylated by ATP, reduced by NADPH

Question 25

What is the catalyst in the calvin cycle?

Answer 25

RubisCO

Question 26

How is the calvin cycle regenerated?

Answer 26

RuBP gets hydrolyzed in regeneration - one ATP per RuBP molecule

Question 27

Oxidative phosphorylation

Answer 27

Powered by redox of the electron transport chain

Question 28

Substrate-level phosphorylation

Answer 28

enzyme puts a P group onto an ADP

Question 29

Glycolysis

Answer 29

Breakdown of sugar- catabolic reaction - energy investment and energy payoff

Question 30

What is the net output of glycolysis?

Answer 30

2ATP, 2NADH, 2 Pyruvate (2H2O, 2H+)

Question 31

Does glycolysis require oxygen?

Answer 31

No - it doesn’t care

Question 32

Where does glycolysis happen?

Answer 32

In the cytosol

Question 33

What happens after glycolysis?

Answer 33

It depends on oxygen. If there is oxygen, aerobic respiration will happen. If not, either fermentation or anaerobic respiration

Question 34

What is fermentation?

Answer 34

Regenerates NAH+ from NADH so glycolysis can happen again. Either alcohol (releasing CO2) or lactic acid (produces lactate - no CO2 is produced)

Question 35

What is anaerobic respiration?

Answer 35

Respiration that uses another electron acceptor other than oxygen - may use nitrogen or sulfur - no electron transport chain

Question 36

Aerobic respiration

Answer 36

O2 - electron transport chain - pyruvate is oxidized into acetyl CoA - each pyruvate loses a CO2

Question 37

Respiration

Answer 37

Pyruvate oxidation (pyruvate –> acetyl CoA) - gives off CO2, NAD+ to NADH, Coenzyme A added

Citric Acid Cycle - each acetyl CoA combines with oxaloacetate –> citrate (CoA is released) –> needs to regenerate oxaloacetate

Question 38

Citric Acid Cycle

Answer 38

Citric Acid Cycle - each acetyl CoA combines with oxaloacetate –> citrate (CoA is released) –> needs to regenerate oxaloacetate