Biomolcules and DNA structure

Question 1

four classes of large biological molecules in all living things:

Answer 1

1. Carbohydrates (sugars and starches)
2. Lipids (fats, oils, phospholipids)
3. Proteins
4. Nucleic acids

Question 2

Polar molecule

Answer 2

• The poles of the molecule have different charges due to the unequal sharing of electrons = charged molecule.
• Hydrophilic - Polar things dissolve in water

Question 3

Nonpolar molecule

Answer 3

The poles of the molecule carry no charge
* Hydrophobic - Uncharged things are repelled by water

Question 4

Monomers

Answer 4

small building-block molecules

Question 5

Polymers

Answer 5

long molecules consisting of many monomers
Synthesis and breakdown of polymers

Question 6

Dehydration synthesis

Answer 6

Forming a covalent bond while losing a water molecule. Building polymers.

Question 7

Amino Acids

Answer 7

• Carboxyl group
• Amino group
• R groups (side chains give amino acid different properties)
• Polypeptide = a polymer of amino acids
• Linked by covalent bonds called peptide bonds
• Polypeptides are unique linear sequence of amino acids, with a carboxyl end (C-terminus) and an amino end (N-terminus)

Question 8

Four Levels of Protein Structure

Answer 8

1. Primary structure – the sequence of amino acids
2. Secondary structure - coils and folds in the polypeptide chain
3. Tertiary structure – folds due to interactions among various side chains (R groups)
4. Quaternary structure - multiple polypeptide chains

Question 9

DNA is type of nucleic acid:

Answer 9

1) A phosphate
2) A sugar (deoxyribose for DNA nucleotides, ribose for RNA)
3) One of four nitrogenous bases
1. Adenine (A)
2. Guanine (G)
3. Thymine (T) or Uracil (U) in RNA
4. Cytosine (C)