Module 1.2: Basic Chemistry of Life II

Question 1

Lipids are unique

Answer 1

among the biomacromolecules because most of them are insoluble in water.

Question 2

Fatty acids are composed of

Answer 2

A zigzag line of long non-polar hydrocarbon chains

Question 3

Triglycerides are the most

Answer 3

abundant lipids in living organisms.

Question 4

After eating, triglycerides are stored within

Answer 4

adipocytes (fat cells).

Question 5

Phospholipids contain two main components:

Answer 5

(1) a polar head group joined to (2) a non-polar tail group

Question 6

phospholipids are considered to be

Answer 6

amphipathic as amphi- means ‘of both kinds’.

Question 7

The head group is composed of

Answer 7

a charged phosphate group and (usually) a nitrogen-containing group.

Question 8

The head is attracted to polar substances, such as water, and therefore is

Answer 8

hydrophilic (water loving).

Question 9

The tail group

Answer 9

is a hydrocarbon

• a molecule containing an H and C—

composed of non-polar fatty acid chains.

Question 10

The tail repels water and is therefore

Answer 10

hydrophobic (water fearing).

Question 11

Steroids are

Answer 11

a type of lipid

made up of four, fused carbon rings

attached functional groups, often containing an alcohol (-OH) group.

Question 12

Cholesterol is an

Answer 12

essential structural component of animal cell membranes

when found in excess, cholesterol in the blood forms plaque on artery walls, leading to an increased risk of heart attack.

Question 13

Proteins are constructed from

Answer 13

monomers called amino acids.

Question 14

Amino acids are

Answer 14

organic compounds

building blocks of protein.

Question 15

Proteins also form enzymes
What is an enzyme?

Answer 15

(catalysts that speed up chemical reactions)

Question 16

Proteins are used to make needed substances such as

Answer 16

hemoglobin, which carries oxygen in red blood cells.

Question 17

What are essential amino acids?

Answer 17

Amino acids that must be obtained from foods in the diet

Question 18

non-essential amino acids can

Answer 18

be manufactured by the human body.

Question 19

Phenylketonuria (PKU)

Answer 19

Inherited condition, error in gene that codes the enzyme Phenylalanine hydroxylase

Without this enzyme, essential amino acid phenylalanine cannot be broken down, builds up in blood- can result in death

Treated with a diet low phenylalanine (essential amino acid)

Question 20

Peptide bonds are

Answer 20

covalent bonds that hold amino acids together to form proteins.

Question 21

Polypeptide

Answer 21

A long chain of amino acids linked together by peptide bonds

Question 22

Primary structure

Answer 22

Specific sequence of amino acid monomers in a linear polypeptide chain

Question 23

Secondary structure

Answer 23

• two repeating patterns that may occur in a polypeptide chain

Some regions/patterns can form 1) spring-like coil

2) while regions/payterns can form a sheet-like structure.

Question 24

α-helix is

Answer 24

a spring-like coil configuration that comprises the basic structural unit of some fibrous proteins that make up wool, hair, skin, and fingernails.

Question 25

Collagen

Answer 25

an important protein in skin, tendons and ligaments, provides elasticity and strength because of its triple helix structure.

Question 26

ß-sheet is formed

Answer 26

when a polypeptide chain snakes back and forth alongside itself, making a pleated sheet that is strong and flexible, but not elastic.

Question 27

hydrogen bonding occurs

Answer 27

between the hydrogen atom of the NH group and the oxygen atom of the C=O bond in order to hold the configuration in place

Question 28

A single polypeptide chain may include both

Answer 28

α-helix regions and ß-sheet regions.

Question 29

Tertiary structure

Answer 29

This is the overall three-dimensional shape assumed by each individual polypeptide chain.

Question 30

Quaternary structure

Answer 30

Formation occurs when two or more polypeptide chains interact (to make a protein)

Question 31

Hemoglobin is an example

Answer 31

of a globular protein composed of four polypeptide chains.

Question 32

Nucleic Acids

Answer 32

Have chemical molecules that carry genetic information within the cell.

Question 33

There are two major types of nucleic acids:

Answer 33

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

Question 34

Nucleic acids are

Answer 34

polymers built from monomers called nucleotides.

Question 35

Each DNA nucleotide may contain one of four different nitrogenous bases:

Answer 35

adenine (A),

thymine (T)

cytosine (C)

guanine (G)

All Tigers Can Growl

Question 36

Each RNA nucleotide may also contain one of four different bases:

Answer 36

adenine (A)

uracil (U)

cytosine (C)

guanine (G)

All Unicorns Can Growl

**uracil **is the difference from DNA nucleotide

Question 37

Why is hydrogen bonding important?

Answer 37

In proteins hydrogen bonds make a-helix & b-sheet regions