respiration Flashcards
what are autotrophs?
organisms that are able to synthesise their own usable carbon compounds from CO2 in the atmosphere through photosynthesis
what is the formula for glucose?
C6H12O6
what are heterotrophs?
are organisms that require pre-made usable carbon compounds which from they get their food
what is light energy transformed to from the sun?
into chemical potential energy
what is respiration?
it’s the release of energy from living cells from the breakdown of organic molecules
what is the main function of the mitochondria?
to synthesize ATP
describe the inner phospholipid membrane of the mitochondria
folded (cristae), less permeable, site of the electron transport chain, location of ATP synthase enzymes
describe the outer phospholipid membrane of the mitochondria
smooth, permeable to several small molecules
describe the intermembrane space of a mitochondria
has a low pH due to the high conc of protons, the conc gradient across the inner membrane is formed during oxidative phosphorylation
describe the matrix in the mitochondria
an aqeuous solution within inner membranes of the mitochondrian, contains ribosomes, enzymes and circular mt DNA
label all the structures inside a mitochondria
matrix, ribosome, outer membrane, inner membrane, intermembrane space, cristae, mitochondrial DNA, granule
how is the structure of a mitochondria aid the function?
- large SA because of cristae so more electron transport chains can be held on the membrane
- more active cells can have larger mitochondria with longer and tighter packed cristae
what is the order of the 4 stages of aerobic respiration
glycolysis, link reaction, krebs cycle, oxidative phosphorylation
what are the products gained from glycolysis?
2 pyruvate molecules, net gain 2 ATP, 2 NADH
what reactants are needed for glycolysis
ATP, NAD, glucose
what are the steps of glycolysis
1) (phosphorylation) of glucose by 2ATP to form fructose biphosphate
2) (lysis) happens and aplits into 2 triose phosphate molecules
3) (oxidation) H is removed from each TP and given to NAD to form NADH
4) (dephosphorylation) 4 phosphates are added to 4ADP’s to form 4ATP
5) the 2 TP is converted to 2 pyruvates
what are the products of link reaction?
acetyl coA, CO2, NADH
how does pyruvate move into the matrix from the cytosol?
when oxygen is available, pyruvate enters mt matrix through the double membrane of the mitochondria via active transport. requires a transport protein and small amount of ATP
what happens during the link reaction?
pyruvate is oxidised by enzymes to produce acetate and CO2, requiring the reduction of NAD to NADH. combinatio with coenzyme A to form acetyl coenzyme A
what does coenzyme A consist of and used for?
has a nucleotide and a vitamin. used in link reactions and supplies the acetyl group to the krebs cycle
where does the krebs cycle take place?
in the matrix of the mitochondria
outline the stages for krebs cycle
2 acetyl coenzyme A (2Cc enter -> adds onto oxaloacetate (4c) -> makes citrate (6c) -> coenzyme A released in this reaction -> citrate converted back to oxaloacetate through redox reactions
how is oxalacetate regenerated from citrate?
decarboxylation of citrate (releases CO2 as waste gas) + oxidation of citrate which releases H atoms that reduce coenzyme NAD and FAD + substrate level phosphorylation which makes 1 ATP from ADP
how many ATPS are created through aerobic respiration? and where do they come from
NADH x 10 -> 25 ATP
FADH x 2 -> 3ATP
ATP (glycolysis) -> 2 ATP
krebs cycle -> 2 ATP
total = 32 ATP
where does oxidative phosphorylation take place?
takes place in the inner mitochondrial membrane
what is the current model called for oxidative phosphorylation called?
the chemiosmotic theory
