15Chapter 2: Introduction to Chemistry

Question 1

All living and non-living things consist of _______.

Answer 1

Matter

Question 2

List the 4 elements that make up about 96% of our body weight.

Answer 2

1. Carbon
2. Nitrogen
3. Hydrogen
4. Oxygen

Question 3

What elements are S, Na, Mg, and Fe?

Answer 3

Sulfur
Sodium
Magnesium
Iron

Question 4

What are the symbols for Potassium, Chlorine, Hydrogen?

Answer 4

K, Cl, H, C

Question 5

Isotope

Answer 5

Atoms of the same element that differ slightly in mass.

Question 6

Radioactive Isotope

Answer 6

An isotope that is unstable and emits radiation (energy) as it breaks down.

Question 7

Electrolyte

Answer 7

An ionic compound (salt, acid, or base) that beaks apart into cations and anions when dissolved.
– conducts electric current.

Question 8

What kind of charges are carried by cations and anions?

Answer 8

Cation= positive charge 
Anion= negative charge

Question 9

Ionic bond *give example

Answer 9

Positively charged ions that are attracted to one another (weak bond)
example= sodium chloride (table salt)

Question 10

Covalent Bond *give example

Answer 10

When atoms form a molecule by sharing one, two, or three pairs of their outer shell electrons
example: hydrogen (H2), oxygen (O2), methane (CH4), and water(H2O)

Question 11

What is the pH of blood?

Answer 11

7.35-7.45

Question 12

The atoms of the isotopes of a particular element vary in their number of __________.

Answer 12

Neutrons

Question 13

Which element is needed for clotting and muscle contraction, and contributes to the hardness of teeth and bone?

Answer 13

calcium

Question 14

What type of bonds hold water molecules together?

Answer 14

covalent bonds

Question 15

The more _______ ions present in a solution, the more basic the solution.

Answer 15

Hydrogen

Question 16

An acid is a substance that dissociates in H2O into one or more _______ ions and one or more _______.

Answer 16

Hydrogen / anions

Question 17

Organic compounds always contain?

Answer 17

Hydrogen and carbon

Question 18

The most plentiful lipid in the human body is ________.

Answer 18

Triglyceride

Question 19

“Saturated fat” is saturated with what?

Answer 19

Hydrogen

Question 20

Steroids are classifies as ______.

Answer 20

Lipids

Question 21

In RNA, the base that is present instead of thymine is ________.

Answer 21

Uracil

Question 22

ATP belongs to the category of compounds known as what?

Answer 22

Nucleic Acids

Question 23

How is ATP the “energy currency” of the cell?

Answer 23

ATP releases energy stored in its 2 high-energy phosphate bonds.

Question 24

How does RNA differ from DNA chemically and physically?

Answer 24

Chemically:
RNA nucleotides are made up of the sugar ribose,
DNA nucleotides are made up of deoxyribose.
Physically:
RNA is single-stranded,
DNA is double-stranded.
RNA uses uracil while 
DNA uses thymine.

Question 25

Structure of DNA

Answer 25

DNA is a large molecule consisting of two helically wound chains of nucleotides. The two chains are held together by hydrogen bonding between the nitrogenous base pairs -Adenine and thymine (A,T) -Cytosin and granine (C,G)

Question 26

Nucleotides

Answer 26

Building blocks of nucleic acids. | Made up of a nitrogen base, a pentose sugar, and one or more phosphate groups.

Question 27

What is the function of an enzyme?

Answer 27

Enzymes are biological catalysts that have specufic "active" binding rates for certain substrates. Enzymes low energy of activation so that reactions in cell can occur at appropriate rate.

Question 28

What are the 4 chemical groups of an amino acid?

Answer 28

1. hydrogen 2. an amine 3. a carboxyl 4. a side chain (R group)

Question 29

What are the 3 important types of lipid and their functions?

Answer 29

1. Triglycerides - energy storage 2. Phospholipids - membrane structure 3. Steroids - hormone membrane structure

Question 30

Lipids

Answer 30

Include most of the substances that are insoluble in H2O but soluble in non-polar solvents such as chloroform or ether.

Question 31

Monosaccharides *give example

Answer 31

Simple sugars made up of C, H, and O. | examples= glucose, fructose, and deoxyribose

Question 32

Buffer

Answer 32

Combination of chemicals that minimizes changes in the pH of a solution when acids and bases are added.

Question 33

pH

Answer 33

A measure of the hydrogen ion concentration of a solution.

Question 34

Salt *when added to water

Answer 34

When put into water, a salt is a substance that dissociates into cations and anions neither of which is (H+) or (OH-) example = sodium chloride

Question 35

Base *when added to water

Answer 35

When put into water, a base is a substance that dissociates into hydroxide (OH-) ions and one or more cations. Also can be descrided as having the capacity to pick up one or more hydrogen (H+) ions.

Question 36

Acid *when added to water

Answer 36

When put into water, an acid is a substance that dissociates into hydrogen ions and one or more anions.

Question 37

Hydrogen Bond

Answer 37

Extremely weak bonds between 2 atoms - important for giving proteins and enzymes their 3-dimensional shapes, bonding specialized molecules such as hormones and receptors, and for binding enzymes to substrates.

Question 38

A substance that ____ is considered to be a chemical compound.

Answer 38

Has covalent bonds

Question 39

When is a ionic bond formed?

Answer 39

two cations meet

Question 40

The ionization of a sodium atom to produce Na+ is an example of what?

Answer 40

anabolism

Question 41

A substance capable of dissolving freely in water is _____.

Answer 41

amphipathic

Question 42

How is a carboxyl group symbolized?

Answer 42

-COOH

Question 43

What is that only polysaccharide synthesized in the human body?

Answer 43

glycogen

Question 44

What it the arrangement of a polypeptide into a fibrous or globular shape called?

Answer 44

tertiary structure

Question 45

The feature that most distinguishes a lipid from a carbohydrate is that a lipid has _____________.

Answer 45

a lower ratio of oxygen to hydrogen