Week 2 - Biochemistry

Question 1

What is biochemistry?

Answer 1

Application of chemistry (atoms) to living (biological) systems (cells)

Question 2

What are inorganic compounds?

Answer 2

• Lack carbon
• E.g. water, minerals

Question 3

What are organic compounds?

Answer 3

• Contain carbon
• E.g. glucose

Question 4

How important is H2O in our bodies?

Answer 4

• H2O is the bodies solvent
• Primary substance in the human body capable of doing many things
• E.g. transports substances, regulate temperature.

Question 5

What is hyrdophilic?

Answer 5

• Water-soluble = Substances dissolve in H2O
• Molecules must be (1) charged (e.g., Na+
  , Cl-) or (2) polar (e.g., glucose)
• Hydration spheres form around them

Question 6

What is hydrophobic?

Answer 6

• Substances that cannot dissolve in H2O
• Non-polar or neutral (no charge) molecules have no attraction to H2O

Question 7

What are the 4 categories of organic compounds?

Answer 7

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleotides (DNA, RNA)

Question 8

What are organic compounds composed of?

Answer 8

• Composed of complex macromolecules, called polymers.
• It is built from basic units known as monomer.

Question 9

What are carbohydrates?

Answer 9

• Hydrophilic macromolecules
• Monomer is C6H12O6
• Carbon that is hydrated with water (H2O)
• Quick source of energy

Question 10

What is monosaccharides?

Answer 10

• Composed of a monomer
• E.g. glucose, fructose, galactose

Question 11

What is disaccharides

Answer 11

• Composed of 2 monomers
• E.g. sucrose which is glucose + fructose

Question 12

What is polysaccharides?

Answer 12

• Composed of many monomers
• Polymers of glucose
• E.g. glycogen (energy storage, 10h), cellulose, starch.

Question 13

What are lipids?

Answer 13

• Hydrophobic
• Chains of C and H (dense fuel source)

Question 14

What are the 4 types of lipids?

Answer 14

1) Fatty acids (saturated and unsaturated)
2) Triglycerides (fats and oils)
3) Phospholipids
4) Steroids (cholesterol)

Question 15

What are triglycerides?

Answer 15

• It is a monomer which is composed of 3 fatty acids bonded to glycerol.

Question 16

What are phospholipids?

Answer 16

• It is one fatty acid replaced by a phosphate group
• Phospholipids assemble into membrane-bound spheres

Question 17

Explain the structure of phospholipids

Answer 17

• Phosphate head is polar (hydrophilic)
• Fatty acid tail is non-polar (hydrophobic)

Question 18

What is the primary structure of proteins?

Answer 18

• Sequence (chain) of amino acids encoded by DNA, produced by cellular ribosomes

Question 19

What is the secondary structure of proteins?

Answer 19

• Coiling (α) or folding (β) of the amino acid chain
• Held by hydrogen and ionic bonds, hydrophobic and hydrophilic attractions
• Tertiary (3-D) and Quaternary (multiple chains) structure

Question 20

What are enzymes (ase)?

Answer 20

• Proteins that enhance speed or likelihood of a chemical reaction occurring (catalyst)
• Act upon a Substrate
• May require a mineral and or vitamin to function

Question 21

What happens to denaturation of proteins>

Answer 21

Extreme heat and pH changes break chemical bonds etc. and cause conformational
(shape) changes that destroy enzyme function

Question 22

What are nucleic acids?

Answer 22

• Polymers of nucleotides
• Deoxyribonucleic acid (DNA)
• < 20 000 human genes (codes for proteins)
• DNA is assembled into forty-six human chromosomes

Question 23

What are nucleotide consists of?

Answer 23

1) deoxyribose (sugar)
2) phosphate group
3) nitrogenous base (carbon ring(s): Adenine (A), Guanine (G), Cytosine (C), Thymine (T)

Question 24

What is DNA?

Answer 24

• Double-stranded
• Two sugar-phosphate backbones (2 polymers)
• Nitrogenous bases (AGCT) linked by hydrogen bonds
• Generates a spiral staircase

Question 25

What is the genetic code (AGCT)?

Answer 25

This 4-letter alphabet of bases is arranged into the 3-letter words that code for the twenty amino acids that form the proteins that build and operate living systems

Question 26

What is RNA?

Answer 26

• Ribonucleic acid
• Single polymer of nucleotides
• Thymine replaced by uracil
• Involved in protein synthesis, ribosome structure, RNA-based enzymes, gene activation
  etc.