bioenergetics

Question 1

which has the lowest Km? hexokinase or glucokinase

Answer 1

hexokinase, higher affinity for glucose

Question 2

what is the similar molecule in the chloroplast to complex III?

Answer 2

cytochrome complex, both involved in a Q cycle

Question 3

what carries electrons, 2 at a time, to complex III?

Answer 3

ubiquinone, then changes to ubiquinol
AKA complex Q10

Question 4

what carries electrons one at a time to complex 4?

Answer 4

cytochrome c

Question 5

describe basic ATP synthase structure

Answer 5

catalytic knob with beta subunits is in matrix, while C ring aka rotor is embedded in the inner membrane.

Question 6

how does UCP1 effect the ETC?

Answer 6

accelerates the ETC and produces heat

Question 7

what kind of animals have a lot of UCP1?

Answer 7

hibernating animals

Question 8

what happens to the inner membrane when the mitochondria are heated up

Answer 8

becomes leaky, less ATP produced as a result

Question 9

how does the number of subunits effect amount of ATP made?

Answer 9

increasing number of subunits decreases ATP production, because more protons are needed to turn the rotor.

Question 10

how many protons does the complex 1 pathway pump versus the complex 2/succinate pathway?

Answer 10

10 e- vs 6 e-

Question 11

how many ATP are made per rotation of the ATP synthase?

Answer 11

3

Question 12

what is the complex between photosystems II and I?

Answer 12

cytochrome complex, has a Q cycle on it, but uses plastiquinone rather than ubiquinone.

Question 13

where do the protons in the thylakoid space come from?

Answer 13

splitting of water. the electrons from here fill the electron holes in the acceptor chlorophyll

Question 14

where do the electrons in photosynthesis come from?

Answer 14

light hits a chlorophyll, gets excited and causes an ACCEPTOR chlorophyll to release electrons.

Question 15

what carries electrons from cytochrome complex to photosystem I?

Answer 15

plastocyanin

Question 16

in cyclic electron flow, where are the electrons from photosystem I feeded into?

Answer 16

plastoquinone
then changes to plastoquinol

Question 17

if you shine blue light on chlorophyll, what happens?

Answer 17

it gets stressed and turns red after leaf cut off tree, since there is no water to split to get electrons from

Question 18

what is photorespiration?

Answer 18

when rubisco binds to O2 instead of CO2 in the calvin cycle

Question 19

how can we avoid photorespiration?

Answer 19

C4 plants -> they take a 3C molecule, and fixes a CO2 into it and transports it directly to the calvin cycle. It uses ATP though, which is likely supplied by cyclic electron flow

Question 20

complex 4 aka?

Answer 20

cytochrome C oxidase

Question 21

true or false, mitochondria have cholesterol

Answer 21

false

Question 22

Which of these is water soluble? NADH or FADH2

Answer 22

NADH

Question 23

which are the three irreversible enzymes of glycolysis?

Answer 23

HK
PFK
PK

Question 24

where does glycolysis get its NAD+ from in the abscence of O2?

Answer 24

lactate dehydrogenase turning pyruvate into lactate, uses 2 NADH -> NAD+

Question 25

NADH moves ___ more H+ than FADH2

Answer 25

4

Question 26

what two factors effect proton motive force?

Answer 26

charge gradient concentration gradient

Question 27

why do mitochondria form cristae in terms of physical structure?

Answer 27

two ATP synthases make a dimer which fold the inner membrane

Question 28

what are the two ways of transport of NADH into the mitochondria?

Answer 28

Malate aspartate shuttle G3PDH shuttle

Question 29

features of the G3PDH shuttle vs the malate aspartate shuttle?

Answer 29

the malate aspartate shuttle is slow and complicated but efficient (transfer of NADH -> NAD+ then enter then back to NADH) G3PDH uses FADH2, is rapid, but loss of 1 ATP.

Question 30

what are the two main stages of photosynthesis?

Answer 30

the light dependent reaction and the calvin cycle

Question 31

where do the light dependent reactions and the calvin cycle occur?

Answer 31

light reactions occur in the thylakoid membrane, the calvin cycle occurs in the stroma.

Question 32

the thylakoid membrane is impermeable to most ions apart from?

Answer 32

Mg2+ and Cl-

Question 33

which photosystem is 680+ and which is 700?

Answer 33

photosystem II is 680+ photosystem I is 700

Question 34

what may explain structure of grana?

Answer 34

cyclic electron flow

Question 35

the calvin cycle uses __________ (the products of the light reactions) to ___________?

Answer 35

ATP and NADPH, produce glucose from CO2

Question 36

____ rounds of the calvin cycle are required to make one glucose because?

Answer 36

two, two G3P make one glucose

Question 37

downfalls of rubisco for farmers?

Answer 37

efficiency drops with temp (binds more O2 rather than CO2) global warming slow growing plants

Question 38

hypothesis for rubisco action being bad?

Answer 38

evolved in a low O2 world

Question 39

C4 plants can?

Answer 39

concentrate CO2 into oxaloacetate for the Calvin cycle

Question 40

constant blood glucose level?

Answer 40

80mg/ml or 5nM

Question 41

features of glycogen

Answer 41

insoluble stored in cytosol synthesised by insulin broken down by glucagon has alpha 1,4 and 1,6

Question 42

what ensures we dont have a futile cycle of glycogen storage and breakdown?

Answer 42

adrenaline/epinephrine

Question 43

how much ATP does gluconeogenesis use?

Answer 43

11-12

Question 44

what are the bypass enzymes?

Answer 44

pyruvate carboxylase, PEPCK F1,6P G6P

Question 45

dont forget that insulin is also important for?

Answer 45

growth! IGF1 and IGF2 insulin is the most powerful growth hormone

Question 46

beta cells produce ______ while alpha cells produce ______

Answer 46

insulin, glucagon

Question 47

insulin ______ gluconeogenesis

Answer 47

stimulates

Question 48

difference between type 1 and 2 diabetes?

Answer 48

type 1 (insulin dependent) has no functioning beta cells, type 2 they begin with insulin insensitivity, then eventually to no insulin production due to beta cells being overwhelmed.

Question 49

bees vs snapping shrimp vs swordfish

Answer 49

bee is very anaerobic -> good O2 supply snapping shrimp directly uses ATP swordfish uses glycogen and anaerobic but has to stop after little bit because lactate is acidic

Question 50

which type of diabetes did best and McCloudwin win their nobel prize for?

Answer 50

Type 1, associated with weight loss.

Question 51

how to manage type 1 and 2 diabetes?

Answer 51

type 1= give insulin type 2= sulfonylureas