5.7.1 need for cellular respiration

Question 1

Pi

Answer 1

inorganic phosphate

Question 2

define metabolism/metabolic reactions

Answer 2

all chemical reactions which occur in living cells

Question 3

what is the energy produced (from organic molecules eg. glucose) from respiration used for

Answer 3

used to synthesise molecules of ATP from ADP & inorganic phosphate (Pi)

Question 4

why do microorganisms, plants, animals, fungi & protoctists respire

Answer 4

to obtain energy

Question 5

define anabolic reactions

Answer 5

metabolic reactions where large molecules are synthesised by smaller molecules (condensation reaction)

Question 6

define catabolic reactions

Answer 6

metabolic reacts involving hydrolysis of larger molecules to smaller ones

Question 7

examples of why living organisms need energy from respiration

Answer 7

used to make ATP to drive biological processes, eg:
- active transport
- endocytosis
- exocytosis
- synthesis of larger molecules, such as proteins eg. collagen
- DNA replication
- cell division
- movement eg. flagella, cilia
- activation of chemicals

Question 8

structure of ATP

Answer 8

= phosphorylated nucleotide

• adenine (nitrogenous base)
• ribose (5-carbon sugar)
• 3 phosphate groups

Question 9

stability of ATP

Answer 9

• relatively stable in solution in cells
  but
• readily hydrolysed by enzyme catalysis

Question 10

why is ATP a good energy source

Answer 10

• when hydrolysed to ADP & Pi = small quantity of energy released for use in cells & thus, can obtain energy needed in small/manageable amounts
• instant energy source in cell
• small & soluble = easily transported around cell
• universal energy currency

Question 11

role of ATP synthase in formation & breakdown of ATP

Answer 11

1. ATP hydrolysed into into ADP & Pi
   - energy released for cells
   - heat released
2. condensation reaction forms ATP from ADP & Pi
   - energy supplied from organic substrate, during respiration