5.2.2 Respiration

ATP is used for (7)

-movement

-active transport

-endo/exocytosis

-cell division: mitosis & meiosis

-synthesis of biological molecules

-DNA replication

aerobic respiration steps (4)

glycolysis (cyto)

link reaction(mito matrix)

krebs cycle(mito matrix)

oxidative phosphorylation(mito inner membrane cristae)

glycolysis

-first step for anae/aerobic respiration

-anaerobic process

glycolysis process

-phosphorylating glucose to hexose bisphosphate

-using 2 ATP and hydrolysing them to release phosphate group

-this binds to glucose (phosphorylating it)

-makes the glucose molecule gain energy and become more reactive

-therefor splits into 2 molecules of triose phosphate

-which undergoes oxidation as NAD picks up H from triose phosphate

-triose phosphate loses a phos grp each and gives to ADP to make ATP

-NAD reduced, triose phosphate oxidised to pyruvate

-pyruvate and NADH actively transported from cyto to mito matrix

products of glycolysis

2x pyruvate

net gain of 2 ATP

2 x reduced NAD

glycolysis diagram

link reaction

-pyruvate further oxidised into acetate (2C)

-NAD picks up H (from pyruvate) and becomes reduced NADH

-decarboxylation; removal of C molecule from pyruvate to form CO₂

-acetate combines w/ coenzyme to produce acetylcoenzyme a

-happens so coenzyme can help acetate enter krebs cycle

how many times does link reaction occur per molecule of glucose

twice

products of link reaction

2x acteylcoenzyme a

2x CO2

2x reduced NAD

link reaction diagram

krebs cycle

acetyl(2C) grp released from conenzyme

combines w/ oxaloacetate(4C) to form citrate (6C)

citrate decarboxylated and dehydrogenated to produce 5C compound

releases CO₂ and NADH

5C compound further decarboxylated and dehydrogenated to 4C compound

substrate level phosphorylation occurs to phosphorylate ADP to ATP

releases CO₂ and NADH

4C compound combines with conenz A temporarily then is released

ATP produced

4C compound dehydrogenated stays 4C

produces reduced FAD

4C catalysed by enzyme and further dehydrogenated

NAD gets reduced

produces oxaloacetate

products made per krebs cycle

products per glucose molecule

krebs cycle diagram

total coenzymes from 1 glucose molecule

10 red. NAD

2 red. FAD

oxidative phosphorylation

NADH dehydrogenised

H split into e^- and protons

e^- picked by proteins embedded in inner mito membrane and passed along e^- transfer chain

every time electron is passed along to next protein

releases enough energy to transport proton to intermembrane space

results in electrochemical gradient due to build up of protons

protons move down this gradient through ATP synthase

as protons move down conc gradient via facilatated diffusion

this will catalyse the phosphorylation of ADP to ATP

at the end of e^- transport chain, O collects e^- and some protons so chain can continue

to form water

oxidative phosphorylation diagram

anaerobic respiration animal

occurs in cyto of cell

pyruvate produced in glycolysis

stays in cyto

reduced to lactate

by gaining H from NADH

oxidises NAD so can be reused in glycolysis

so more ATP produced

anaerobic respiration animal diagram

anaerobic respiration plant and microbes

pyruvate decarboxylated to produce ethanal

reduced to produce ethanol by gaining H from NADH

anaerobic respiration plant diagram

respiratory substrate

organic molecule that can be used in respiration to produce ATP

glucose most common

respiratory substrate (carbs)

used in glycolysis

glucose or starch( plants)

glycogen (animals)

can be hydrolysed to release glucose

respiratory substrate (lipids)

hydrolysed into glycerol and fatty acids

glycerol converted into triose phosphate

enters glycolysis to make pyruvate

fatty acids combine w/ coenzyme A

then converted to acetyl coenzyme a to enter krebs cycle

respiratory substrate (proteins)

hydrolysed to amino acids

deaminated to release keto acids

used in krebs

respiratory quotient

ratio of CO2 molecules produced compared to O molecules produced in respiration

RQ formula

CO2 produced/ O2 produced

RQ of carbs

1.0

RQ lipids

0.7

RQ proteins

0.8-0.9

RQ anaerobic respiration

above 1.0

what does RQ show

substrate being used in aerobic respiration

respirometer

device used to measure the rate of exchange of O and/or CO2 in living organism during aerobic respiration