Chapter 2: The Chemical Level of Organization

Question 1

What are the 4 major elements that constitute about 96% of the body’s mass?

Answer 1

Oxygen, Carbon, Hydrogen, Nitrogen

Question 2

What are the 8 other lesser elements that contribute to the 3.6% to the body’s mass?

Answer 2

Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, Magnesium, Iron

Question 3

What do you call the type of elements that makes up the remaining 0.4% of the body’s mass?

Answer 3

Trace elements

Question 4

Describe what a free radical is.

Answer 4

an atom or group of atoms with an unpaired electron in the outermost shell. Having an unpaired electron makes them unstable, highly reactive, and destructive to nearby molecules.

Question 5

How do free radical become stable?

Answer 5

They either give up their unpaired electron or take an electron from another molecule.

Question 6

What is an antioxidants?

Answer 6

Substances that inactivate oxygen-derived free radicals.

Question 7

What does antioxidants do when it gets consumed?

Answer 7

It is thought to slow the pace of damage caused by free radicals. An example of antioxidants include selenium, zinc, beta-carotene, and vitamins C and E.

Question 8

What is a valence shell?

Answer 8

outermost shell of an atom

Question 9

Describe anion and cation.

Answer 9

Anion is a negatively charged ion, while cation is a positively charged ion

Question 10

What is an electrolyte?

Answer 10

An ionic compound that breaks apart into positive and negative ions in solution

Question 11

What is an ion?

Answer 11

an atom that has a positive or negative charge because it has an unequal numbers of protons and electrons.

Question 12

What is a covalent bond?

Answer 12

2 or more atoms sharing electrons rather than gaining or losing them

Question 13

Describe what’s in a polar covalent bond.

Answer 13

sharing of electrons between 2 atoms is unequal with a resulting molecule that has a partial negative charge near the atom that attracts electrons more strongly

Question 14

Describe what’s in a non-polar covalent bond.

Answer 14

2 atoms share electrons equally. The bonds between 2 identical atoms are always non-polar

Question 15

Describe a hydrogen bond.

Answer 15

This type of bond result from attraction of opposite and partially charged parts of molecules rather than sharing, gaining or losing of electrons. It is a very weak bond and is mainly to give structure. It is also easy to break apart.

Question 16

Peptide

Answer 16

bond between amino acids in a protein

Question 17

Chemical reactions

Answer 17

occurs when bonds break or form. When a bond breaks apart it releases energy and when a bond forms, it restores energy

Question 18

What is a chemical energy?

Answer 18

a form of potential energy stored in the bonds compounds and molecules

Question 19

Synthesis reactions

Answer 19

collectively referred as anabolism and it is when 2 or more atoms, ions, or molecules combine to form new and larger molecules

Question 20

Why are anabolic reactions usually endergonic?

Answer 20

because they absorb more energy than they release

Question 21

Decomposition reaction

Answer 21

collectively referred as catabolism and it is when large molecules split up into smaller molecules, ions, or atoms

Question 22

Why are catabolic reactions usually exergonic?

Answer 22

because they release more energy than they absorb

Question 23

Reversible reaction

Answer 23

can either go right or left based on the conditions existing in your body. In other words, the products can revert to the original reactants.

Question 24

Oxidation-Reduction reactions

Answer 24

Oxidation refers to the loss of electrons and the oxidized substance releases energy. While reduction refers to the gain of electrons and the reduced substance gains energy.

Question 25

Activation energy

Answer 25

The collision energy needed to break the chemical bonds of the reactant

Question 26

Organic compounds

Answer 26

always contain carbon, usually contain hydrogen, and always have covalent bonds. Most are large molecules, many with long carbon atom chains. Makes up the remaining 38-43% of the human body

Question 27

Inorganic compound

Answer 27

usually lacks carbon and are structurally simple. Their molecules have a very few atoms and cannot be used to perform complicated biological functions. They include water, many salts, acids and bases.

Question 28

Hydrolysis

Answer 28

break down of large molecules into smaller molecules by the addition of water molecules

Question 29

Dehydration synthesis reaction

Answer 29

when two smaller molecules join to form a larger molecule. In other words, getting rid of water in that molecule

Question 30

Hydrophobic

Answer 30

fears water or not very water-soluble. Molecules that contain mainly non-polar covalent bond. Such compound includes animal fats and vegetable oils.

Question 31

Hydrophilic

Answer 31

loves water or they easily dissolve in water. Solutes that contain polar covalent bond. Common examples of hydrophilic solutes are sugar and salt.

Question 32

Colloid

Answer 32

a homogenous substance that differs from a solution because the size of its particles are large enough to scatter light thats why they usually appear translucent or opaque.