Biological Molecules - Lecture 0.1

Question 1

Name the ions that make up the mass of the human body

Answer 1

Nitrogen, oxygen, hydrogen and carbon make up 96% of the bodys weight

Question 2

Ion

Answer 2

an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Question 3

Cation

Answer 3

positively charged ion

Question 4

Anion

Answer 4

negatively charged ion

Question 5

Calciums key roles

Answer 5

blood clotting, muscle contraction. secondary messenger needed for neurotransmitter release, establishing sustained depolarization in cardiac action potentials

Question 6

Hydrogen key roles

Answer 6

acid-base balance; forms proton gradient necessary to make ATP in mitochondria (cellular respiration)

Question 7

Bicarbonate key roles

Answer 7

acid-base balance

Question 8

potassium key roles

Answer 8

membrane potentials. Most abundant cation INSIDE cells

Question 9

sodium key roles

Answer 9

membrane potentials; water balance; most abundant cation in interstitium and plasma

Question 10

What types of bonds provide energy for the body to do work?

Answer 10

Exergonic and Endergonic reactions

Question 11

Explain exergonic reactions

Answer 11

EXIT - RELEASE; they release energy. Example of catabolism; more stable bonds are created from less stable ones

Question 12

Catabolism

Answer 12

breaking down of molecules

Question 13

Explain an example of an exergonic reaction

Answer 13

cellular respiration - glucose is oxidized into water, CO2 and energy (ATP)

Question 14

Explain endergonic reactions

Answer 14

ENTER - ABSORB; absorb energy; example of anabolism; less stable bonds are created from more stable bonds

Question 15

anabolism

Answer 15

molecules are being made

Question 16

What is an example of an exergonic reaction

Answer 16

condensation reactions that make AA and polypeptides

Question 17

what is the relationship between exergonic and endergonic reactions?

Answer 17

Exergonic reactions (catabolism) make endergonic reactions (anabolism) possible. ie: oxidation of glucose (exergonic) provides the ATP to make some AA synthesis (endergonic) possible.

Question 18

How is a covalent bond formed?

Answer 18

electron sharing among atoms

Question 19

What is the relationship between covalent bonds and endergonic reactions?

Answer 19

When a covalent bond is broken, energy is released which can then be used to synthesize reactions

Question 20

Explain anabolism in covalent bonding

Answer 20

Used in forming covalent bonds and requires some sort of input of energy

Question 21

Explain catabolism in covalent bonding

Answer 21

Would indicate the breaking of covalent bonds and this releases energy

Question 22

What does energy have to do with covalent bonds?

Answer 22

Energy is needed to form them and this energy is released when these bonds are broken

Question 23

What is polarity?

Answer 23

separation of electric charge due to the unequal sharing of electrons among the constituent atoms thus resulting in a positive and negative dipole

Question 24

Why is water polar?

Answer 24

because oxygen holds onto electrons more strongly than hydrogen

Question 25

What is a hydrogen bond?

Answer 25

Electromagnetic attraction between dipole moments

Question 26

Define dipole moment

Answer 26

unequal electron sharing created by differences in electronegativity between the atoms in a compound

Question 27

Explain hydrogen bonds role in energy.

Answer 27

Hydrogen bonds are not true chemical bonds, therefore broken H bonds cannot provide energy for endergonic reactions.

Question 28

What is the chemical formula for glucose?

Answer 28

C6 H12 O6

Question 29

What is a glucose?

Answer 29

A monosaccharide (carbohydrate)

Question 30

Explain the structure of a lipid

Answer 30

glycerol attached to three FA chains

Question 31

What do lipids (triglycerides) do?

Answer 31

Principal storage form of energy (adipose cells); protect and insulate

Question 32

Explain the importance of glycerol?

Answer 32

important molecule necessary to carry out gluconeogenesis in liver

Question 33

What is the structure of a phospholipid?

Answer 33

2 FA attached to a phosphorylated molecule

Question 34

What is the importance of the phosphorylated molecule in the phospholipid?

Answer 34

It results in a polar (water loving) head and non polar (hydrophobic) tail

Question 35

The importance of phospholipids

Answer 35

They are the major component of cell (plasma) membranes with their polar heads on the outside and non polar fatty acid tails on the inside

Question 36

What is the role of cholesterol?

Answer 36

helps maintain cell membrane stability and permeability to transmembrane proteins and it is a precursor for the biosynthesis of steroid hormones, bile acids and vitamin D

Question 37

Describe the structure of cholesterol

Answer 37

Has polar and non polar moieties making it amphipathic. The polar moieties hydrogen bond with the phosphorylated heads of the lipid bilayer and its non polar moieties bind with the phospholipid tails via van Der waal forces

Question 38

What are proteins?

Answer 38

large, complex molecules made up of AA and linked in sequence by covalent peptide bonds

Question 39

Describe the parts of a protein

Answer 39

N-terminus which is the alkaline amino group, C-terminus which is the acidic carboxyl group and an R-group that is the side chain which is different for each AA and determines the AA chemical property. Variations in the sequence/number of AA produces a different protein.

Question 40

The relationship between hormones and proteins

Answer 40

Some important hormones are protein. Peptide hormones include insulin, glucagon and ADH (vasopressin)

Question 41

Define chemical bond.

Answer 41

Forces created by electrons which hold atoms together to form molecules and compounds.

Question 42

Examples of chemical bonds

Answer 42

covalent bond and ionic bond

Question 43

define ionic bond

Answer 43

ionize in water forming essential electrolytes

Question 44

define molecules

Answer 44

a combination of two or more atoms

Question 45

Define compound

Answer 45

a chemical substance consisting of 2 or more different chemical elements that can be separated into simpler substances

Question 46

Example of compound

Answer 46

sucrose

Question 47

Define ion

Answer 47

any atom or molecule where the number of electrons and protons are unequal and has an electric charge, either positive or negative