Chapter 3 (Biochemistry)

Question 1

Ions are formed when…

Answer 1

… atoms gain or lose electrons to form positively or negatively charged ions

Question 2

Covalent bonding

Answer 2

atoms are sharing electrons

Question 3

example on hydrogen bonds

Answer 3

with water molecules, the positively charged hydrogen atoms of one molecule are attracted to negatively charged oxygen atoms of nearby water molecules (hydrogen bonds)

Question 4

Sulphur

Answer 4

important element in some amino acids

Question 5

Calcium

Answer 5

which is found in bones / Teeth, important for muscle contraction

Question 6

Iron

Answer 6

found in haemoglobin (animal)

Question 7

Sodium

Answer 7

needed for a nerve impulse

Question 8

Phosphorus

Answer 8

found in cell membrane structures, nucleic acids (DNA and RNA)

Question 9

Cohesion

Answer 9

water molecule is sticking to another water molecule (sticking together of alike molecules)

Question 10

Adhesion

Answer 10

the force by which individual molecules cling to surrounding material and surfaces

Question 11

Phospholipid

Answer 11

• similar chemical structure to triglyceride
• one of the fatty acid group is replaced by phosphate
• the phosphate is ionized and soluble in water
• phospholipids combine the hydrophobic properties of the hydrocarbon tails with hydrophilic properties of the phosphate
• form monolayers and bilayers in water
• phospholipid bilayer is a major component of the plasma membrane of cells.

Question 12

Enzymes

Answer 12

biological catalysts made of protein

Question 13

Active site

Answer 13

region of an enzyme molecule where the substrate molecule binds

Question 14

Substrate

Answer 14

a molecule upon which an enzyme reacts

Question 15

denaturation

Answer 15

structural change in a protein that alters its three-dimensional shape and causes the loss of its biological properties