Unit 5 - Respiration Flashcards by Matthew Beattie

Respiration

Process by which energy stored in complex organic molecules is released and immediately transferred to ATP
Energy is released through hydrolysis (making new bonds)

How well did you know this?

Not at all

Perfectly

Why do animals need energy

Active transport 
Endo/exocytosis
Synthesis of protein
DNA replication 
Cell division 
Movement 
Activation of a chemical (phosphorylation)

How well did you know this?

Not at all

Perfectly

Catabolic

Releasing energy

How well did you know this?

Not at all

Perfectly

Anabolic

Energy consuming

How well did you know this?

Not at all

Perfectly

ATP

Intermediary between catabolic and anabolic reactions
Relatively stable, only broken down by hydrolysis by enzyme catalysis (energy released can be controlled)
Easily moved around a cell when in solution

How well did you know this?

Not at all

Perfectly

Hydrolysis of ATP

Catalysed by ATPase
ATP is hydrolysed to produce ADP then again to produce AMP
ATP –> ADP (-30.5), ADP –> AMP (-30.5), AMP —> A (-13.8)

How well did you know this?

Not at all

Perfectly

Structure of ATP

Ribose attached to adenine (phosphodiester bond)
3 inorganic phosphate groups
Phosphorylated nucleotide

How well did you know this?

Not at all

Perfectly

Processes in aerobic respiration

Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation

How well did you know this?

Not at all

Perfectly

Glycolysis

Occurs in cytoplasm
Phosphorylation —> hexose biphosphate (2 phosphate groups from 2 ATP)
Hexose biphosphate splits into two
Oxidation (removal of H atoms) - accepted by NAD to make NADH
Breaks down glucose into pyruvate (3C), 2 NADH and 2 ATP

How well did you know this?

Not at all

Perfectly

Where does glycolysis occurs

Cytoplasm

How well did you know this?

Not at all

Perfectly

Why are ATP used in the first stage of glycolysis

Provide activation energy

How well did you know this?

Not at all

Perfectly

Where does oxidative phosphorylation occur

Cristae

How well did you know this?

Not at all

Perfectly

Role of ATP in the cell

Universal currency of energy
Phosphates can be removed by hydrolysis to release 30 kJ/mol energy
Energy used in metabolic reactions
Energy released in small quantities to prevent cell damage

How well did you know this?

Not at all

Perfectly

Where does the Kreb’s cycle occur

Matrix of mitochondria

How well did you know this?

Not at all

Perfectly

Coenzymes in leaf

NAD and FAD can be reduced to NADH and FADH2 and act as hydrogen carriers
NADPH reduces molecules by adding e-
ATP phosphorylates
Coenzyme A carries acetate to Kreb’s cycle

How well did you know this?

Not at all

Perfectly

Link reaction

Pyruvate is decarboxylated to acetate (+ CO2)
Combines w/ CoA to make acetyl coenzyme A
Happens twice for glycolysis
Produces 2 NADH

How well did you know this?

Not at all

Perfectly

Kreb’s cycle

CoA is recycled back to link reaction
Acetate combines with oxaloacetate to make citrate
Decarboxylated 2x to give orig. 4C compound, oxaloacetate
Produces 6 NADH, 2 FADH2 , 2 ATP and 4 CO2 (substrate level phosphorylation)

How well did you know this?

Not at all

Perfectly

Which cofactor is part of the ETC

Fe^2+

How well did you know this?

Not at all

Perfectly

What’s found in the matrix

Enzymes 
NAD
FAD
Oxaloacetate 
Mitochondrial DNA
Mitochondrial ribosomes

How well did you know this?

Not at all

Perfectly

Mitochondrial DNA

Codes for mitochondrial enzymes and other proteins

Mitochondrial ribosomes

Where proteins are assembled

Where can fatty acids be used in respiration

Fatty acids can produce acetate and enter the Kreb’s cycle directly

Where can glycerol be used in respiration

Can be converted to pyruvate and enter the link reaction

Where does the link reaction occur

Matrix of mitochondrion

Theoretical yield of ATP from 10 NADH

Total theoretical yield of ATP per pyruvate

25 - NADH 2 - FADH2 1 - Krebs cycle 2 - glycolysis =30

Why is the yield of ATP not 100%

ATP has to be used for active transport of pyruvate and NADH

Vol. of CO2/ Vol. of O2 per unit time

RQ value for glucose

RQ value for AA

0.8/0.9

RQ value for triglycerides

0.7

Investigating respiration rates of yeast

Put a known vol. and conc. of a substrate sol. into a tt Add a known vol. of buffer soln. - keep pH constant Place tt in water bath (25 degrees) Add known mass of dry yeast After yeast has dissolved, place a bung on the tt which is attached to a gas syringe (should be set to 0) Start the stopwatch Record vol. of CO2 produced at regular intervals and calculate rate

Using a respirometer to measure O2 consumption

Set up respirometer - one w/ glass beads and the other w/ woodlice of same vol. Add KOH to both - absorbs CO2 produced Use syringe to set fluid in manometer to known level Measure distance travelled by liquid in manometer - gives you vol. of O2 used up (pi r^2 h - need diameter of capillary tube)

Why does the liquid move in the manometer

As the woodlice use up the O2, pressure decreases causing coloured liquid in manometer to move towards tt

Limitation of using respirometer

Diff to accurately read the meniscus of the fluid in the manometer

Substrate level phosphorylation

ATP is formed by the direct transfer of Pi to ADP | Only occurs in Glycolysis and Kreb's cycle

Substrate level phosphorylation in glycolysis

2 ATP per each glucose, when TP is converted to pyruvate | 4 - 2 = 2

Substrate level phsophorylation in Kreb's cycle

1 per each turn | Occurs when 5C compound is converted to oxaloacetate

NAD vs FAD

NAD used in all stages but FAD only in Kreb's NAD accepts 1 H, FAD accepts 2 H's NADH is oxidised at the start of the etc releasing e- and H+ while FADH2 is oxidised further along the chain NADH synthesises 3 ATP but FADH2 synthesises 2 ATP

Oxidative phosphorylation

FADH2 and NADH deliver H to etc in cristae H dissociates into H+ and e- (used in synthesis of ATP through chemiosmosis) Energy is released as e- travel down etc, creates a proton gradient At end of etc, e- combines w/ H+ and O2 --> water Etc cannot operate w/out oxygen

Obligate anaerobes

Cannot survive on the presence of oxygen at all

Facultative anaerobes

Synthesie ATP by aerobic respiration if oxygen is present but can switrch to anerobic e.g. yeast

Obligate aerobes

Can only synthesise ATP in the presence of oxygen e.g. mammals

Fermentation

Produces ATP through substrate level phosphorylation only, no involvement of etc

Alcoholic fermentation

Occurs in yeast and some root cells Glycolysis occurs and pyruvate is decarboxylated to ethanal Ethanal accepts H+ from NADH to produce ethanol and NAD (recycled) Produces ethanol and CO2

Lactate fermentation

Carried out in animal cells and produces lactate Glycolysis occurs as normal Lactate dehydrogenase causes pyruvate to accept H from NADH and is converted to lactate and NAD (recycled) Allows glycolysis to keep occurring

Where is lactic acid converted back to glucose

Liver but requires oxygen --> oxygen debt after exercise

Why can lactate fermentation not occur indefinitely

Reduced ATP isn't enough to sustain vital processes | Accumulation of lactic acid leads to fall in pH, proteins denature (respiratory enzymes)