C1.2 Cell Respiration

3 parts of nucleotides

• Nitrogen-containing base

• Five-carbon sugar

• Phosphate groups

Roles of ATP (+ draw structure of ATP molecule)

• Energy transfer

• Active transport

• Protein pump

• Muscle contraction

• Building large molecules

Locomotion

Movement

Macromolecules synthesis

Linking monomers into large polymers

Active transport

Pumping ions/other particles across a membrane

Steps of ATP-ADP Cycle

• ATP + phosphate + energy → (condensation) ADP +H2O

• ADP + H2O → (hydrolysis) ATP + phosphate + energy

Cell Respiration

Cells deriving energy from glucose

Consequences of cell respiration producing uncontrolled amounts of glucose

• Glycolysis wouldn’t happen

• Large amounts of glucose will be released

• Bodily functions won’t work (e.g; digestion)

Aerobic respiration

Respiration that takes place in the presence of oxygen

Formula for Aerobic Respiration

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

Anaerobic Respiration

Respiration that takes place without the presence of oxygen

Formula for Anaerobic respiration

glucose + lactate (+ATP)

Lactate

Lactic acid

Differences between aerobic and anaerobic respiration

AEROBIC	ANAEROBIC
Glucose and lipids can be used	Only carbs can be used
CO2 and H2O are the waste products	CO2 + lactate are the waste products
Yields 30 ATP per glucose	Yields 2 ATP per glucose
(include formula)	(include formula)
Initial reaction happens in the cytoplasm, more happens in mitochondria	Only happens in cytoplasm
Requires oxygen	Doens’t require oxygen

(some) Differences between muscle and yeast anaerobic respiration

Muscle	Yeast
End product: lactic acid	End product: ethanol
Sore muscles occur here

3 measuring techniques for cell respiration

• Sealed glass/plastic container

• A base

• A capillary tube

Oxidation

Loss of hydrogen electrons from a substance

Reduction

Gain of hydrogen electrons from a substance

Electron carrier

Substances that can accept and lose electrons reversibly

Main electron carrier in respiration

Nicotinamide Adenine Dinucleotide (NAD)

Glycolysis

The breakdown of glucose and converting it to pyruvate

Formula for glycolysis

glucose + 2 NAD⁺ + 2ADP + 2P_i → 2pyruvate + 2NADH + 2H⁺ + 2ATP

Stages of glycolysis

1. Phosphorylation of glucose

2. Lysis

3. Oxidation

4. ATP Formation

Process of forming regenerating NAD in production of ethanol in yeast

• CO2 is removed from pyruvate, making ethanol

• 2H atoms are transferred from NADH+ to ethanal, making ethanol

Yeast

Unicellular fungus that occurs naturally in habitants where glucose or other sugars are available

Facultative Anaerobe

Capable of respiring aerobically & anaerobically

Reactant and products of Link reaction

• Pyruvate

• 1 CO2

• 1 NADH+

Outline the Link reaction

• This is where pyruvate is converted into acetyl groups

• Pyruvate is changed in two ways during the link reaction:

  • Decarboxylation- CO2 is removed

  • Oxidation- Pair of H atoms is removed 

• An acetyl group remains- links to a carrier molecule: CoA

• Acetyl-CoA is produced

Krebs Cycle

• Happens in the matrix and mitochondrion

• CO2 is removed

• Hydrogen is removed in four reactions

• ATP is produced directly in one of the reactions

How many carbons does oxaloacetate have

4

How many carbons does citrate have

6

What’s in the inner mitochondrial membrane

Groups of proteins that act as electron carriers

Where does reduced NAD come from

• Glycolysis

• Link reaction

• Krebs Cycle

Electron Transport Chain

Sequences of electron carriers in the inner mitochondrial membrane

Consequences of oxidation in phosphorylation

• NADH⁺ is oxidised

• Protein gradient is created

Chemiosmosis

Process used to couple the proton gradient to synthesis of ATP

Formation of ATP by ATP synthesis

1. ADP and phosphate bind to different parts of the active site

2. Conformational change to the active site forces ADP and phosphate together

3. ATP is produced

4. Active site returns to its original conformation

5. ATP is released and active site becomes more vacant

Processes by which lipids can be a substrate for respiration

• Lipids are broken down into fatty acids

• Fatty acids are activated by attaching them to coenzyme A (CoA)

• Oxidative phosphorylation happens

• CO₂ is the waste product

Carbohydrates vs lipids table