BIOLOGICAL MOLECULES

Question 1

How are hydrogen bonds reflected?

Answer 1

As dashes

Question 2

Why is a water molecule dipolar?

Answer 2

Because the oxygen has a slightly negative charge and the hydrogen has a slightly positive charge.

Question 3

What is a metabolite?

Answer 3

A substance made or used when the body breaks down food, drugs or chemicals

Question 4

What is a solvent?

Answer 4

A solvent is a substance which has the ability to dissolve solutes.

Question 5

What is a solute?

Answer 5

The substance being dissolved.

Question 6

What is a solution?

Answer 6

A homogeneous mixture of one or more substances

Question 7

Why does water have a high specific heat capacity?

Answer 7

Water molecules are stuck to each other meaning a lot of energy is required to break down bonds due to their hydrogen bonds.

Question 8

Why is it an advantage that water has a high specific heat capacity?

Answer 8

Because water acts as a buffer against sudden temperature variations making aquatic environments a temperature stable one. Most organisms are mostly water so it buffers them against certain temperature changes.

Question 9

How does latent heat of vaporisation work in water?

Answer 9

Hydrogen bonding between water molecules means it requires a lot of energy to vaporise 1 gram of water. This is very effective in the evaporation of sweat because it means body heat is used for cooling to evaporate the water.

Question 10

What is cohesion in molecules?

Answer 10

The tendency of molecules to stick together.

Question 11

What does water’s cohesive forces allow it to do?

Answer 11

Water has large cohesive forces which allows is to be pulled up by a tube such as a xylem vessel in plants.

Question 12

What is surface tension?

Answer 12

Surface tension in water is when water acts like skin eg when water meets air molecules tend to be pulled back to the body of water rather than escaping from it.

Question 13

How is water a metabolite?

Answer 13

1. ) Water is produced in condensation reactions

2. )Water is used to break down many complex molecules in hydrolysis eg proteins to amino acids

Question 14

How is water an important solvent?

Answer 14

Water dissolves other substances such as oxygen and carbon dioxide , ammonia and urea and enzymes whose reactions take place in solutions.

Question 15

What are enzymes?

Answer 15

Enzymes are globular proteins that act as catalyst.

Question 16

What are catalyst?

Answer 16

Catalyst alter the rate of a chemical reaction without undergoing permanent changes themselves.

Question 17

What is the activation energy?

Answer 17

The activation energy is the minimum amount of energy needed to activate the reaction.

Question 18

How do enzymes effect activation energy and how is this an advantage?

Answer 18

Enzymes work to lower activation energy meaning that enzymes allow reactions to take place at a much lower temperature. This enables metabolic reactions to take place at 37 degrees and without these enzymes chemical reactions wouldn’t be able to sustain life.

Question 19

How do enzymes lower the activation energy?

Answer 19

They bind to the substrate and allow a chemical bond-breaking-bond-forming process to happen more easily.

Question 20

Why is the active site important?

Answer 20

The active site has a specific shape for each enzymes and substrates with a complementary shape to the active site of an enzyme bind to form an enzyme-substrate complex.

Question 21

What is the shape of the active site determined by?

Answer 21

The tertiary structure of the polypeptide.

Question 22

What is a polypeptide?

Answer 22

A polypeptide is a polymer made of many amino acids joined together by peptide bonds.

Question 23

What does a tertiary structure describe?

Answer 23

The three dimensional shape of proteins.

Question 24

What is the structure globular proteins?

Answer 24

Globular proteins are compact, spherical and soluble in water

Question 25

What is the structure of an active site?

Answer 25

An active site is made up of a small number of amino acids and forms a small depression within the larger enzyme molecule.

Question 26

What is the correlation between value and water potential?

Answer 26

The more negative the value, the lower the water potential.