respiration Flashcards
state the two types of anaerobic resp.
- alcoholic fermentation
- lactate fermentation
what are the two main similiarities between the two types of anaerobic resp. ?
- occur in cytoplasm
- start at glycolysis
what occurs during lactate fermentation ?
pyruvate is converted to lactate (lactic acid) using H+ from NADH
how is lactate removed from the body?
the liver converts it back into glucose by gluconeogenesis
what occurs during alcoholic fermentation ?
- CO2 removed from pyruvate to form ethanal
- NADH transfers H+ to ethanal forming ethanol
what are the four stages in aerobic respiration ?
glycolysis, link reaction, Krebs cycle and oxidative phosphorylation
where does aerobic resp occur ?
glycolysis - cytoplasm
other 3 - mitochondria
what occurs during glycolysis ?
one molecule of glucose (6C) is split into two pyruvate molecules (3C)
does glycolysis require oxygen ?
no
what are the two parts of glycolysis ?
phosphorylation and oxidation
describe phosphorylation in glycolysis
- glucose phosphorylated with 2 phosphates (from 2 ATP) to form hexose bisphosphate
- then split into two molecules of triose phosphate
describe the oxidation in glycolysis
- triose phosphate oxidised (loses hydrogen) to form 2 pyruvate molecules
- 2 NAD form 2 reduced NADH
- 4 ATP produced (net gain of 2)
what occurs during link reaction ?
- pyruvate is decarboxylated (CO2 formed)
- pyruvate loses hydrogen (goes to NAD) to form acetate
- acetate combines w/ coenzyme A
- forms acetyl coA
how many link reactions occur each glucose ?
two
how many krebs cycles occur each glucose ?
two
state the steps involved with Krebs cycle in order
acetyl group 2C from acetyl CoA + oxaloacetate - citrate 6C - 5 carbon compound - 4 carbon compound
what is substrate level phosphorylation ?
when phosphate group directly transferred to another molecule
what are the products of Krebs cycle ? (6)
- CoA
- oxaloacetate
- 2 CO2
- 1 ATP
- 3 NADH
- FADH2
what is oxidative phosphorylation ?
process where energy carried by enzymes from reduced co enzymes (NADH and FADH) is used to make ATP
where does oxidative phosphorylation occur ?
inner mitochondrial membrane
what is chemiosmosis ?
process of ATP production driven by H+ movement across membrane moving down an ETC
what is the total ATP made from one glucose ?
32
what causes diff resp substrates to have diff energy values ?
abundance of hydrogen atoms per unit mass for oxidative phosphorylation (lipids contain most)
respiratory quotient =
vol of CO2 produced / vol of O2 consumed
a respiratory quotient over 1 means …
anaerobic resp
outline process of chemiosmosis in mitochondria (6)
- H atom split into protons and electrons
- e- moves along ETC
- energy from e- used to pump protons
- electrochemical gradient formed
- protons move down gradient via ATP synthase (movement drives production of ATP)
- protons, electrons and oxygen combine to form water at end of ETC
what is oxygen said to be in chemiosmosis ?
the final electron acceptor
where do protons move from / to in chemiosmosis ?
from mitochondrial matrix —> inter membrane space
how many ATP per reduced NAD?
2.5
how many ATP per reduced FAD?
1.5
state the RQ for a carb
1
state the RQ for a protein / amino acid
0.9
state the RQ for lipid
0.7
RQ =
vol of CO2 released / vol of O2 consumed
why do lipids have highest energy value when respired ?
- most ATP made in ox. phosphorylation
- requires H atoms from coenzymes
- lipids contain most hydrogen per unit mass
low RQ means …
high level of oxygen
RQ over 1 means …
short of oxygen so there is some anaerobic resp.
why do plants tend to have low RQ ?
CO2 produced from respiration used straight away in photosynthesis
where does glycolysis occur ?
cytoplasm
where does link reaction occur ?
mitochondrial matrix
where does Krebs cycle occur ?
mitochondrial matrix
where does oxidative phosphorylation occur ?
inner mitochondrial membrane
what enzyme used in krebs cycle ?
citrate synthase
how many carbons in citrate ?
6C
