biology module 9

kinase

enzyme; phosphorylates a protein

• takes place in: nucleus, cytoplasm, mitochondria, cell membrane

phosphatase

enzyme; dephosphorylates a protein

• takes place in: nucleus, cytoplasm, mitochondria, cell membrane

what molecule is this

ATP

cellular respiration

cells convert chemical energy (food) into ATP

• requires glucose + enzymes + molecular “shuttles” (NADH) + a chemical “pull” (oxygen)

cellular respiration is a series of

redox reactions

redox reactions

oxidation-reduction reactions or chemical reactions that involve transferring of electrons between two species

NADH

electron carrier

oxidation

substance loses electrons; becomes oxidized

reduction

substance gains electrons; positive charge amt becomes reduced

reducing agent

electron donor; reduces electron acceptor

oxidizing agent

electron acceptor; oxidizes electron donor

fermentation

chemical process; molecules like glucose are broken down anaerobically

• produces energy + regenerates NAD+ for glycolysis + produces lactate/ethanol

substrate phosphorlyation

donation of phosphate group from a substrate to ADP

2 goals of glycolysis + location

• break down glucose

• produce energy

cytoplasm (outside mitochondria)

without glycolysis

neurodegeneration + enzyme deficiency + cancer

• cells malfunction or die

glucose to glucose 6-phosphate

1st step of glycolysis (energy investment phase)

• hexokinase phosphorylates glucose

glucose 6-phosphate to fructose 6-phosphate

2nd step of glycolysis (energy investment phase)

• phosphogluco-isomerase rearranges the sugar to be split evenly

fructose 6-phosphate to fructose 1, 6-bisphosphate

3rd step of glycolysis (energy investment phase)

• phospho-fructokinase phosphorylates fructose 6-phosphate

fructose 1, 6-bisphosphate split in half into G3P + DHAP

4th step of glycolysis (energy investment phase)

• aldolase splits glucose (6C) in half (into 2 3C molecules)

DHAP to G3P

5th step of glycolysis (energy investment phase)

• isomerase converts DHAP to G3P

G3P to 1, 3-bisphospho-glycerate

6th step of glycolysis (energy payoff phase)

• triose phosphate dehydrogenase collects electrons via (2) NAD+ carriers

  • 2 NADH & 2 H⁺

1, 3-bisphospho-glycerate to 3-Phospho-glycerate

7th step of glycolysis (energy payoff phase)

• phospho-glycerokinase mediates 1st substrate level phosphorylation

  • 1 ADP to 1 ATP

3-Phospho-glycerate to 2-Phospho-glycerate

8th step of glycolysis (energy payoff phase)

• phospho-glycero-mutase rearranges the molecule

2-Phospho-glycerate to PEP

9th step of glycolysis (energy payoff phase)

• enolase rearranges molecule + releases water as a waste-by-product

PEP to pyruvate

10th step of glycolysis (energy payoff phase) [END OF GLYCOLYSIS]

• pyruvate kinase mediates 2nd substrate level phosphorlyation

  • 1 ADP to 1 ATP

  • [END] = 2 PYRUVATE + 2 NADH + 2 ATP

products produced per glucose molecule

2 ATP 2 PYRUVATE 2 NADH

pyruvate oxidation goals + location

• make acetyl-CoA

• produce energy carrier

mitochondrial matrix

decarboxylation

1st step of pyruvate oxidation

• carboxl group removed; forms CO2

oxidation

2nd step of pyruvate oxidation

• NAD+ gets reduced to NADH

• mediated by pyruvate dehydrogenase complex

Coenzyme A attachment

3rd step of pyruvate oxidation [END]

• coenzyme A attached to acetate; forms acetyl CoA

products of pyruvate oxidation

2 Acetyl-CoA , 2 NADH + H⁺ , 2 CO₂

kreb’s cycle goal + location

• oxidize acetyl-CoA

• produce energy

mitochondrial matrix

electron transport chain goal + location

• creates proton gradient

• produces energy

mitochondrial membrane

fill in blanks

filled dih

products of kreb’s cycle

oxaloacetate, 4 CO2, 2 ATP, 6 NADH + H⁺ , 2 FADH₂

products of electron transport chain

30-32 ATP, Protons, NAD⁺, FAD

anaerobic respiration

done by some species of microorganisms that use non-oxygen electronegative molecules; also form an ETC

fermentation

does not use ETC; another form of substrate-level phosphorlyation; occurs in absence of oxygen

• consists of glycolysis + reactions that regenerate NAD+ for glycolysis

types of fermentation

alcoholic + lactic acid fermentation

alcoholic fermentation

pyruvate converted to ethanol

• CO2 released from pyruvate (forms acetaldehyde)

• acetaldehyde reduced by NADH to ethanol

lactic acid fermentation

pyruvate converted to lactate without producing CO2

• fermentation by bacteria used in food (cheese, yogurt, chocolate, etc)

obligate anaerobes

use fermentation or anaerobic respiration and cannot survive in presence of O₂

facultative anaerobes

yeast + many bacteria use cellular respiration in presence of O₂ or fermentation when O₂ is absent

citrate formation

1st step of Kreb’s Cycle

• Acetyl-CoA (2C) joins oxaloacetate (4C) to form citrate (6C)

  • catalyzed by citrate synthase

Isomerization

2nd step of Kreb’s cycle

• citrate (6C) converted to isocitrate (6C)

  • by aconitase

first oxidation + decarboxylation

3rd step of Kreb’s cycle

• isocitrate (6C) oxidized to α-ketoglutarate (5C)

• reduced NAD+ to NADH and CO2 released

  • by isocitrate dehydrogenase

second oxidation + decarboxylation

4th step of Kreb’s cycle

• α-ketoglutarate (5C) oxidized to succinyl-CoA (4C)

• reduced NAD+ to NADH and CO2 released

  • by α-ketoglutarate dehydrogenase

substrate-level phosphorylation

5th step of Kreb’s cycle

• succinyl-CoA (4C) converted to succinate (4C)

• produces (1) ATP

  • by succinyl-CoA synthetase

oxidation of succinate

6th step of Kreb’s cycle

• succinate (4C) oxidzed to fumarate (4C)

• reduces FAD to FADH₂

  • by succinate dehydrogenase

hydration

7th step of Kreb’s cycle

• fumarate (4C) converted to malate (4C) by addition of water

  • catalyzed by fumarase

regeneration of oxaloacetate

8th step of Kreb’s cycle [END]

• malate (4C) oxidized to oxaloacetate (4C)

• reduces final NAD+ to NADH

  • by malate dehydrogenase

[cycle occurs one more time, doubling products]