Proteins and Lipids

Question 1

What are the general characteristics of proteins?

Answer 1

Used as structural materials and cell function. Ex: Enzymes, hemoglobin, contractile proteins of muscles. Elements in proteins C,H,O,N (many also contain sulfur)

Question 2

Building blocks of proteins

Answer 2

Amino Acids

Question 3

How many amino acids are in total?

Answer 3

20

Question 4

What are the 4 functional groups surrounding a central carbon?

Answer 4

Amino group (-NH2), basic
Carboxyl group (-COOH), acidic 
Hydrogen 
R group ( a group of atoms that gives each amino acid its unique chemical behavior) 20 different R groups

Question 5

Proteins are what?

Answer 5

Long chains of amino acids joined by dehydration synthesis

Question 6

Covalent bonds that joins amino acids.

Answer 6

Peptide Bond

Question 7

Two amino acids joined.

Answer 7

Dipeptide Bond

Question 8

Three joined.

Answer 8

Tripeptide

Question 9

Long chain of amino acids.

Answer 9

Polypeptide

Question 10

Are composed of 1 or more polypeptides folded into a 3-D shape.

Answer 10

Protein

Question 11

Chief building materials of the body. Extended and strand like. Insoluble in water and very stable. Provide mechanical support and tensile strength to body tissues. Ex: collagen in bones, keratin, elastin, contractile proteins of muscles.

Answer 11

Structural proteins

Question 12

Chemical active.

Answer 12

Functional proteins

Question 13

Shape: Compact spherical. Soluble in water. Unstable easily misshapen. Ex: Antibodies, enzymes, protein-based hormones.

Answer 13

Globular Proteins

Question 14

The activity of a protein depends on its 3-D structure. Hydrogen bonds are weak and easily broken but needed for the protein’s 3-D structure. Hydrogen bonds are broken by excessive acidity or heat.

Answer 14

Protein Denaturation

Question 15

Insoluble in water, dissolve in other lipids or organic solvents like alcohol. All contain carbon, hydrogen and small amount of oxygen. Diverse group of molecules, include: phospholipids, neutral fats, steroids.

Answer 15

Lipids

Question 16

Fats

Answer 16

Known as fats when solid.

Question 17

Oils

Answer 17

When liquid at room temperature.

Question 18

A modified simple 3-carbon sugar (sugar alcohol)

Answer 18

Glycerol

Question 19

3 fatty acids join to a glycerol molecule to form?

Answer 19

Triglyceride

Question 20

What makes chains make fats and oils non polar?

Answer 20

Hydrocarbon chains

Question 21

What makes a fat solid and an oil liquid?

Answer 21

Fats have single bonds between carbons; fatty acids are saturated. Oils have double bond between some of the carbons; these fatty acids are unsaturated. The unsaturated fatty acids have fewer hydrogens that they can hold.

Question 22

Bond between carbons produce “kinks” in fatty acid chains. The kinks keep oil molecules apart; thus oils are liquid at room temperature.

Answer 22

Double bond

Question 23

Phosphorus containing group replaces one of the fatty acid chains. Form cell membranes.

Answer 23

Modified triglycerides

Question 24

Flat molecules made of four rings. Cholesterol: found in cell membranes, raw material of Vitamin D.

Answer 24

Steroids

Question 25

What reaction occurs when two amino acids form?

Answer 25

Condensation Reaction

Question 26

Water attracted.

Answer 26

Hydrophilic

Question 27

Water fearing.

Answer 27

Hydrophobic

Question 28

The carbon atoms are in effect full.

Answer 28

Saturated

Question 29

Carbon atoms that are not bonded to the maximum number of atoms to which they can bond.

Answer 29

Unsaturated

Question 30

Cell membrane is made of two layers of phospholipids.

Answer 30

Lipid bilayer