C1.2 ATP

what does ATP stand for

Adenosine triphosphate

where is the energy stored in ATP

in the high energy bond between the phosphates

uses of ATP

active transport, energy storage, moving cell structures, protein synthesis, anabolism

how is energy released

when ATP is hydrolysed to ADP

site of cell respiration

mitochondria

principal substrates for respiration

fatty acids and glucose

respiratory quotant

CO2 produced / O2 consumed

aerobic respiration in animals

glucose + oxygen → carbon dioxide + water (and ATP)

anaerobic respiration in animals and bacteria

glucose→ lactic acid (and ATP)

anaerobic respiration in yeast and plants

Glucose → ethanol + carbon dioxide (and ATP)

Redox reactions

When oxidation and reduction occur (loss and gain of electrons, or hydrogen ions)

NAD

Electron acceptor

Process of glycolysis

Glucose → (2 ATP → ADP) 2x triose phosphate → (4 ADP → ATP, 2 NAD → NADH) 2x pyruvate

What happens in anaerobic respiration

The pyruvate from glycolysis is used to regenerate NADH and this is then used again in glycolysis to generate ATP from Glycerate-3-phosphate. 

What other substrates can be used in respiration

Glucose only in glycolysis

Proteins in krebs cycle (amino acids)

Lipids in krebs cycle

Process of link reaction

Converts pyruvate to acetyl CoA

Pyruvate → (NAD to NADH, CO2 out) acetate → (coenzyme A in) Acetyl CoA

Matrix

Fluid filled, contains enzymes for link and krebs

Cristae

Folded inner membrane, ETC takes place here, large SA

Stalked particles

Have atp synthase for phosphorylation

Krebs cycle process

Citrate (6C) → (CO2 out, NAD to NADH) 5C compound → (CO2 out, NAD to NADH) 4C compound → (ADP to ATP) → (FAD to FADH) → (NAD to NADH) Oxaloacetate (4C)

How many times does the Krebs cycle happen per glucose molecule?

2

Where does the Krebs cycle occur

In the mitochondrial matrix

Process of ETC (part1- water formation)

Electron acceptors (NADH) arrive at inner mitochondrial membrane, NADH is oxidised releasing electrons, electrons flow through ETC (losing energy as they flow). This energy pumps H+ ions from matrix → intermembrane space, creating a chemical concentration gradient. The final protein in the ETC ejects electrons into matrix to combine with Oxygen (final electro acceptor) and H+ ions to form water

Process of ETC (part 2 ATP formation)

The protons creating the concentration gradient repels the H+ back across the membrane. They are forced to flow through a special protein channel connected ATP synthase enzymes. The flow of H+ ions through ATP synthase is called chemiosmosis. 2 H+ ions = 1 ATP. Most H+ ions are then pumped back into the intermembrane space, some form water.

What is oxygen in the ETC

The final electron acceptor