Biological Molecules

Question 1

What are proteins made of?

Answer 1

Proteins are made of amino acids. Proteins are composed of long chains of amino acids. There are 20 different amino acids used in proteins.

Question 2

What do proteins contain?

Answer 2

They all contain carbon, hydrogen, oxygen and nitrogen, and some contain sulfur.

Question 3

How many different types of amino acids are there?

Answer 3

20

Question 4

Describe how proteins are held together.

Answer 4

1) The amino acids in a protein chain are attached to each other by strong peptide bonds.
2) The amino acids can be arranged in any sequence and proteins can be up to several hundred amino acids long.
3) The number of different proteins that are possible is almost unimaginable. Consider that there are several thousand ways of arranging a chain of just 3 amino acids, with each combination forming a different protein.
4) It’s the order of the amino acids in a protein that determines its structure and it’s the structure of a protein that determines how it works

Question 5

What is the primary structure of a protein?

Answer 5

The order in which the amino acids are arranged in a protein chain

Question 6

What type of bond holds together the secondary structure of a protein?

Answer 6

Hydrogen bonds (weak forces of chemical attraction)

Question 7

Give an example of a carbohydrate.

Answer 7

Sugars, starch, cellulose

Question 8

Finish the equation:
GLUCOSE + GLUCOSE –>

Answer 8

MALTOSE (a disaccharide) + WATER

Question 9

Finish the equation:
GLUCOSE + FRUCTOSE –>

Answer 9

SUCROSE (a disaccharide) + WATER

Question 10

What are polymers?

Answer 10

Large molecules made up of monomers (smaller units). The monomers of polysaccharides are monosaccharides.

Question 11

Is starch a monosaccharide or a polysaccharide?

Answer 11

Polysaccharide

Question 12

Is cellulose a monosaccharide or a polysaccharide?

Answer 12

Polysaccharide

Question 13

What are two physical factors of Cellulose molecules?

Answer 13

Cellulose molecules are long and straight.

Question 14

Name two monosaccharides.

Answer 14

Fructose, glucose

Question 15

Which disaccharide is composed of two molecules of glucose?

Answer 15

Maltose

Question 16

Name two polysaccharides?

Answer 16

Starch, cellulose, amylose and amylopectin.

Question 17

What elements do lipids contain?

Answer 17

Carbon, hydrogen and oxygen

Question 18

What are Lipids?

Answer 18

Oils and fats. Plant oils are mostly made up of a group of lipids called triglycerides.

Question 19

What does a triglyceride?

Answer 19

Molecule of glycerol with three fatty acids attached to it.

Question 20

What are phospholipids?

Answer 20

A molecule of glycerol, with two fatty acids and a phosphate group.

Question 21

Cell membranes are made of what?

Answer 21

A double layer of phospholipids.

Question 22

Which elements are fatty acids composed of?

Answer 22

Carbon, hydrogen and oxygen.

Question 23

What’s the difference between saturated fatty acids and unsaturated fatty acids?

Answer 23

Every carbon atom is saturated fatty acid chains is joined by a single bond. Unsaturated fatty acids have one or more double bonds in their carbon chains.

Question 24

What’s the difference between triglycerides and phospholipids?

Answer 24

A triglyceride is made up of one glycerol molecule and three fatty acid molecules but a phospholipid is made of one glycerol molecule, two fatty acid molecules and a phosphate group.

Question 25

Enzymes speed up what?

Answer 25

Biochemical reactions.

Question 26

Enzymes are…?

Answer 26

Globular proteins

Question 27

What is the function of enzymes?

Answer 27

Speed up the rate of biochemical reactions.

Question 28

What is activation energy?

Answer 28

The energy required to get a reaction started.

Question 29

What do digestive enzymes do?

Answer 29

Digestive enzymes break down food into smaller molecules.

Question 30

How does temperature affect enzyme activity?

Answer 30

As temperature increases, the rate of reaction also increases.

Question 31

Why are enzymes described as ‘specific’?

Answer 31

The substrate molecule must be the correct shape to fit into the active site.

Question 32

Explain why a denatured enzyme will not function.

Answer 32

The shape of the active site has changed and the substrate will no longer fit.

Question 33

Describe the effect of pH on enzyme activity.

Answer 33

Acids and alkalis can denature enzymes by disrupting the weak hydrogen bonds in the enzymes’ tertiary structure and changing the shape of their active sites.