Unit 1 Biological Molecules - Water, Inorganic Ions & ATP

Question 1

Describe the structure of ATP & reveal the name

Answer 1

• Adenosine Triphosphate
• Nucleotide Derivative & formed from
  = a molecule of ribose(PENTAGON)
  = a molecule of adenine(RECTANGLE)
  = 3 phosphate groups

Question 2

Describe the function of ATP

Answer 2

• Immediate source of energy for biological processes

- Energy released in hydrolysis is coupled to metabolic reactions in the cell

Question 3

Describe hydrolysis in ATP.

Answer 3

HYDROLYSIS - ATP 🠢 ADP +Pi

• ATP hydrolysed into ADP + Pi(INORGANIC PHOSPHATE) by a hydrolysis reaction using enzyme ATP hydrolase releasing energy
• Allows ions to be moved against a concentration gradient

Question 4

Describe condensation in ATP.

Answer 4

CONDENSATION - ADP + Pi 🠢 ATP
- ATP is made/resynthesised during respiration & photosynthesis from ADP + Pi by a condensation reaction using enzyme ATP Synthase

Question 5

Describe what is meant by phosphorylation

Answer 5

• Inorganic phosphate released during hydrolysis of ATP
• can bond onto different compounds
• to make them more reactive

Question 6

Describe how water is a polar molecule

Answer 6

OXYGEN IS MORE ELECTRONEGATIVE THEAN HYDROGEN
O has a slight negative charge(δ-)
H has a slight positive charge(δ+)
- leading to hydrogen bonding

Question 7

Describe 2 properties of water

S

Answer 7

Water is an important metabolite in many reactions
= Condensation & Hydrolysis
Water is an important solvent in reactions(universal solvent)
= Allows for a transport medium

Question 8

Describe 2 properties of water

L

Answer 8

Water has a high specific heat capacity
= So acts as a buffer against rapid temperature changes
Water has a large latent heat of vaporisation
= Large amounts of energy required to evaporate water
= Allows for cooling effect with small water lost through evaporation(sweat)

Question 9

Describe 1 property of water

Answer 9

Water has strong cohesion between water molecules due to hydrogen bonding
= Allows long columns of water to travel in tube-like transport cells of plants
= Provides surface tension where water meets air

Question 10

Describe where inorganic ions occur

Answer 10

• Inorganic ions occur in solution
• In the cytoplasm and bodily fluids of organisms
• Some in high concentrations and some in very low concentrations

Question 11

Name 2 inorganic ions and their roles

Answer 11

HYDROGEN ION
- Lowers the pH of solutions
- Impacts enzyme function and haemoglobin function
IRON ION
- Component of haemoglobin in the transport of oxygen

Question 12

Name 2 inorganic ions and their roles

Answer 12

SODIUM IRON
- Involved in co-transport of glucose & amino acids in absorption
- Therefore generating concentration gradient for sodium ions
PHOSPHATE ION
- Component of DNA (phosphodiester bond) & used to make ATP