2.2. 1-2 Basics Biochemistry

Question 1

What is a condensation reaction?

Answer 1

(bond making)

reaction that occurs when two molecules are joined together with the removal of H2O

Question 2

What is a hydrogen bond?

Answer 2

a weak interaction that can occur wherever molecules contain a slightly negatively charged atom bonded to a slightly positively charged Hydrogen atom

Question 3

What is a hydrolysis reaction?

Answer 3

(bond breaking)

reaction that occurs when a molecule is split into two smaller molecules with the addition of water

Question 4

What is a monomer?

Answer 4

a small molecule which binds to many other identical molecules to form a polymer

Question 5

What is a polymer?

Answer 5

a large molecule made from many smaller molecules called monomers

Question 6

What is Covalent Bonding?

Answer 6

sharing of a pair of electrons

Question 7

What do 2 monomers make?

Answer 7

dimer

Question 8

Name the atoms of the molecule Carbohydrates and the monomer it makes as well as the polymer

Answer 8

Atoms: C, H, O
Monomer: Monosaccharadies e.g Glucose
Polymer: Polysacchardies e.g Starch

Question 9

Name the atoms of the molecule Protiens and the monomer it makes as well as the polymer

Answer 9

Atoms: C, H, O, N, S
Monomer: Amino acids
Polymer: Polypeptides and protiens

Question 10

Name the atoms of the molecule Nucleic Acids and the monomer it makes as well as the polymer

Answer 10

Atoms: C, H, O, N, P
Monomer: Nucleotides
Polymer: DNA and RNA

Question 11

What does polar mean?

Answer 11

A polar molecule will have dipoles

Question 12

Why is it important for Water to be a liquid at room temperature?

Answer 12

Water has low viscosity which means it can flow easily:

1. Provides Habitats for living things in rivers, lakes, seas
2. Form a major component of the tissues in living organisms
3. Provides a reaction medium for chemical reactions
4. Provides an effective transport medium e.g in blood and vascular tissues.

Question 13

The density of water provides an ideal habitat for living things. Because ice is less dense than water, how does this benefit living organisms?

Answer 13

4°C is the freezing point of water

1. Aquatic organisms have a stable environment in which to live through winter as the water molecules align themselves in a structure which is less dense than liquid water —> It doesn’t sink
2. Ponds and other bodies of water are insulated against extreme cold. The layer of ice reduces the rate of heat loss from the rest of the pond

Question 14

What does solvent mean?

Answer 14

able to dissolve other substances.

Question 15

What does solute mean?

Answer 15

the minor component in a solution, dissolved in the solvent.

Question 16

How does water’s polarity affect its solvent properties?

Answer 16

1. Water is polar —> +ve and -ve parts of the water molecules are attracted to the +ve and -ve part of the solutes.
2. Water molecules cluster around these charged parts of solute molecules or ions and will help separate them and keep them apart.

Question 17

What advantages are there of Water being a good solvent?

Answer 17

1. Molecules and ions can move around and react together in water.
2. and can be transported around living things whilst dissolved in water.
3. Many such reactions happen in the cytoplasm of cells which is over 70% water

Question 18

What is cohesion?

Answer 18

Cohesionholds hydrogen bonds together to create surface tension onwater. Sincewateris attracted to other molecules, adhesive forces pull thewatertoward other molecules

Question 19

What is surface tension?

Answer 19

1. Water molecules at the surface are all hydrogen bonded to the molecules beneath them —> more attracted to the water molecules beneath than to the air molecules above
2. This means the surface of the water contracts —> Gives water an ability to resist force applied to it

Question 20

What are the advantages of Surface tension and cohesion?

Answer 20

1. Columns of water in plant vascular tissue are pulled up the xylem tissue together from the roots
2. Insects like pond-skaters can walk on water

Question 21

Why is having a high specific heat capacity of water important?

Answer 21

1. Living things, including prokaryotes and eukaryotes, need a stable temperature for enzyme- controlled reactions to happen properly
2. Aquatic organisms need a stable environment in which to live

Question 22

What is the specific heat capacity of water

Answer 22

4.2kJ of energy to raise the temperature of 1kg of water by 1°C

Question 23

What is high latent heat of vaporisation and why is it important?

Answer 23

1. When water evaporates, heat energy, known as latent heat of vaporisation, helps the molecules break away from each other to become a gas.
2. This means water can help cool living things and keep their temperature stable.

Question 24

Water is involved in reactions such as photosynthesis and in hydrolysis reactions such as digestions of starch proteins. Is it’s properties as a reactant effected?

Answer 24

It’s properties as a reactant does not directly draw on its polarity, but its role as a reactant is important for digestion and synthesis of large biological molecules