Biology Unit 2 Test

Question 1

Define chemical element

Answer 1

a substance that can not be broken down chemically.

Question 2

List the four elements that form the bulk of body matter.

Answer 2

Hydrogen
Oxygen
Nitrogen
Carbon

Question 3

List the subatomic particles

Answer 3

Proton, Neutron, Electron

Question 4

Describe the relative charges of Protons, Neutrons, and Electrons

Answer 4

Protons are positive
Neutrons are neutral
Electrons are negative

Question 5

Describe the positions of the subatomic particles in the atom.

Answer 5

Protons and Neutrons are in the nucleus and electrons float around outside.

Question 6

T or F Chemical reactions involve the interaction of electrons to make and break chemical bonds.

Answer 6

T

Question 7

Describe ionic bonds

Answer 7

Ionic is the stealing of electrons from atom to atom
Cation = positive
Anion=negative

Question 8

Describe covalent bonds

Answer 8

Covalent is the sharing of electrons from atom to atom

Question 9

Describe hydrogen bonds

Answer 9

A hydrogen bond is an attraction between bonded hydrogen and another electronegative atom.

Question 10

Contrast the relative strengths of covalent, ionic and hydrogen bonds.

Answer 10

Covalent bonds are stronger than ionic bonds and ionic bonds are stronger than hydrogen bonds.

Question 11

Describe a chemical reaction. Be able to recognize the reactants and the products.

Answer 11

A chemical reaction is a cause for a change in a substance. The substance becomes a new substance.

Question 12

Explain the concept of pH and the pH scale.

Answer 12

pH is a measure of H+ concentration on log scale.
7=neutral
pH>7 = base
pH<7 = acidic

Question 13

What is the pH of pure water?

Answer 13

pH7

Question 14

What is the pH of blood?

Answer 14

pH7.35–7.45

Question 15

What is the pH of hydrochloric acid?

Answer 15

pH1

Question 16

Describe the function of carbohydrates.

Answer 16

Carbohydrates are used for energy and structure.

Question 17

Give an example of a monosaccharide, a disaccharide, and a polysaccharide.

Answer 17

Monosaccharide: glucose
Disaccharide: sucrose
polysaccharide: glycogen

Question 18

draw a monosaccharide, disaccharide, and polysaccharide molecule

Answer 18

Check review sheet

Question 19

Describe the function of lipids.

Answer 19

Lipids move and store energy, absorb vitamins, and make hormones.

Question 20

Identify the three main types of lipids and draw their molecular structure.

Answer 20

1. fats
2. phospholipids
3. steroids
   check review sheet for the drawing

Question 21

Describe the functions of a protien.

Answer 21

Start a chemical reaction, structure, storage, transport, regulation/homeostasis, receptors, movement, and defense.

Question 22

Identify the subunit of a protein.

Answer 22

amino acids.

Question 23

List the four main parts of an amino acid.

Answer 23

the amino group, the carboxyl group, the R group, and the Hydrogen atom.

Question 24

Describe the importance of the R group in an amino acid.

Answer 24

The R group changes to make amino acids different.

Question 25

Describe the structure and function of DNA.

Answer 25

DNA looks like a twisted ladder, and it holds instructions for an organism to develop and survive. -A T- -T A- -G C- -C G-

Question 26

Describe the structure and function of RNA

Answer 26

RNA is a single strand twisted ladder and carries messages from the DNA to the cytoplasm. It contains Uracil instead of Thymine. -A U- -T A- -G C- -C G-

Question 27

Explain the importance of ATP in the body.

Answer 27

ATP generates energy for the body.