General Knowledge

Question 1

What is the end-product of digestion of proteins?

Answer 1

Amino acids

Question 2

Which enzymes are found in the microbodies (peroxisomes) and what is their purpose?

Answer 2

Catalase

Catalyses hydrogen peroxide (toxic)to water and oxygen

Question 3

What is the tonoplast?

Answer 3

The membrane around a cell vacuole

Question 4

What are plastids?

Answer 4

These are organelles containing pigments.
Examples of plastids include chloroplasts and leucoplasts

Question 5

What is the cell wall of prokaryotes made of?

Answer 5

Murein (amino acids and polysaccharides)

Question 6

What size are the ribosomes in prokaryotes and eukaryotes respectively?

Answer 6

70S (smaller) in prokaryotes
80 S (larger) in eukaryotes; however the mitochondrial ribosomes and those in chloroplasts are also 70S therefore eukaryotes have both 70S and 80S

Question 7

What makes a substance polar?
And what is the effect of polarity on a substance?

Answer 7

• Uneven charge distribution within the molecules
• Makes it soluble in water eg water molecules are dipolar( , Phosphate heads of phospholipids, carbohydrate heads of glycolipids

Question 8

Which enzyme catalyzes the breakdown of starch to maltose?

Answer 8

Amylase

Question 9

Which enzyme catalyses the breakdown of maltose to glucose?

Answer 9

Maltase

Question 10

What makes a substance polar? And what is the effect of polarity on a substance?

Answer 10

• Uneven charge distribution within the molecules
• Makes it soluble in water eg water molecules are dipolar(Phosphate heads of phospholipids, carbohydrate heads of glycolipids

Question 11

What is the arrangement of four bonds (as in methane) on a carbon atom called?

Answer 11

Tetrahedral arrangement

Question 12

Which hormone converts glycogen to glucose?

Answer 12

Insulin

Question 13

Which hormone stimulates contractions during pregnancy?

Answer 13

Oxytocin

Question 14

Which hormone is responsible for the breakdown of cellulose to glucose?

Answer 14

Cellulase

Question 15

What is special about hydrogen bonds?

Answer 15

• They are individually weak but collectively strong
• Are constantly breaking and being formed

Question 16

What is metabolism?

Answer 16

The sum of biochemical processes in the body

Question 17

Which enzyme catalyzes the breakdown of hydrogen peroxide to water and oxygen gas?

Answer 17

Catalase enzyme

Question 18

Give examples of cells that lack mitochondria

Answer 18

• Red blood cells
• Phloem cells

Question 19

True or false
When fats are oxidized, water is a product

Answer 19

True
(This metabolic water can be useful to desert animals which store fat for this purpose)

Question 20

Are lipids soluble or insoluble and why?

Answer 20

Insoluble

(They are non-polar and their molecules do not form hydrogen bonds with water molecules)

Question 21

What is the protein found in milk called?

Answer 21

Casein

Question 22

Another name for murein (the constituent of the cell wall of prokaryotic cells) is ?

Answer 22

Peptidoglycan

Question 23

Why don’t plant cells burst upon intake of a lot of water but animal cells do?

Answer 23

Plant cells have a rigid cellulose cell wall that prevents bursting of the cell upon intake of water while the cell wall is absent in animal cells (only have a cell membrane) thus it may burst when too much water is taken in.