B1.3-Respiration

Question 1

What is metabolic rate?

Answer 1

The speed at which cells use chemical reactions to transfer energy from its chemical stores in food

Question 3

What are carbohydrates?

Answer 3

Carbohydrates are polymers made from sugar monomers (sucrose,fructose and lactose). Starch is an example of a carbohydrate monomer. Carbohydrase enzymes such as amylase (in your mouth) break down carbohydrates.

Question 4

What happens when food molecules are digested?

Answer 4

They are absorbed by the bloodstream, then travel to the cells that need them.

Question 5

Why do we need food?

Answer 5

We need food for movement,growth and repair of body tissue

Question 6

What are lipids?

Answer 6

Lipids are the fats and oils that you eat. They are not polymers they are synthesised from three fatty acid molecules and a glycerol molecule. Animals use them for buoyancy.

Question 7

What is respiration?

Answer 7

Respiration is when energy is transferred so that you can move,grow and keep warm. The energy comes from chemical stores in the food you eat and they react with oxygen from the lungs in a process called aerobic respiration.

Question 9

What are proteins?

Answer 9

Proteins are polymers made from amino acid monomers (like dna monomer is a nucleotide). There are roughly 20 different amino acids and the codons determine what protein is made. Protease enzyme breaks down protein

Question 10

What is aerobic respiration?

Answer 10

Respiration that uses oxygen

glucose+oxygen—

Question 11

What happens to the energy produced?

Answer 11

The energy produced in respiration is called ATP (adenosine triphosphate) is used:

• To synthesise larget molecules from smaller one to make new material (translation)
• For movement
• To stay warm (homeostasis)

Question 12

Where does respiration occur?

Answer 12

Respiration occurs in the mitochondria

Question 13

Is respiration exothermic or endothermic?

Answer 13

Respiration is exothermic since energy is transferred to the surroundings by heating

Question 14

How much mitochondria does each cell have?

Answer 14

It depends on how active the cell is, for example sperm cells have a lot of mitochondria as they respite a lot because they use a lot of energy

Question 15

What is anaerobic respiration?

Answer 15

Anaerobic respiration is respiration that does not require oxygen

glucose—

Question 16

Why is it better to respire aerobically?

Answer 16

• Aerobic respiration produces more ATP per glucose molecule than anaerobic respiration does
• lactic acid produced can cause cramps. When lactic acid builds up in muscle cells it causes pain and the muscles stop contracting. This is called fatigue.

Question 17

What is oxygen debt?

Answer 17

Oxygen debt is the oxygen needed to break down the lactic acid. That is why people keep breathing heavily after strenuous excercise.

Question 18

Do other organisms anaerobically respire?

Answer 18

Other animals anaerobically respire when they need to transfer a lot of energy quickly, for example when they are being chased by a predator. Anaerobic respiration also occurs in plants (do not need oxygen at all) and some microorganisms. They produce ethanol and carbon dioxide instead of lactic acid.

Question 19

What is fermentation?

Answer 19

Fermentation is when microorganisms respire to produce ethanol (alcohol) it si often used to produce industrial alcohol such as beer

glucose—