chapter 2

Question 1

the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.

Answer 1

Chemistry

Question 2

positively charged particles

Answer 2

protons

Question 3

neutral particles

Answer 3

neutrons

Question 4

Smaller negatively charged particles orbit the nucleus

Answer 4

electrons

Question 5

What is the electric charge of a proton? an electron?

Answer 5

positive, negative

Question 6

a fundamental (pure) form of matter that cannot be broken down to a simpler form.

Answer 6

Element

Question 7

Different atomic forms of the same element, varying only in the number of neutrons they contain. The heavier forms tend to be radioactive.

Answer 7

isotope

Question 8

Particle consisting of two or more atoms joined by chemical bonds. water

Answer 8

molecule

Question 9

that which is not actually performing any work at the moment

Answer 9

Potential energy

Question 10

Energy that is actually doing work

Answer 10

kinetic energy

Question 11

Strong, A bond in which the sharing of electrons between atoms results in each atom having a maximally filled outermost shell of electrons

Answer 11

Covalent bond

Question 12

Moderate The bond between two oppositely charged ions (atoms or molecules that were formed by the permanent transfer of one or more electrons)

Answer 12

Ionic bond

Question 13

An atom or molecule with a positive or negative electric charge.

Answer 13

ion

Question 14

What charge will an ion have if it losses an electron? gains an electron?

Answer 14

positive, then negative

Question 15

What are ions in body fluids (such as Na+, K+, Cl-) called?

Answer 15

electrolytes because solutions of water containing ions are good conductors of electricity

Question 16

Molecules such as water that are electrically neutral overall but still have partially charged regions, or poles,

Answer 16

polar molecule

Question 17

Which type of bond makes adjacent polar molecules stick together?

Answer 17

Hydrogen bonds

Question 18

Oxygen, carbon, hydrogen and nitrogen are?

Answer 18

the four most common elements in living things

Question 19

Summarize why water is essential to life.

Answer 19

Water is the solvent that transports many essential molecules and other particles around the body

Question 20

Differentiate between solvent and solute.

Answer 20

A solute is a substance that is added to a solvent to form a solution. A solvent is a substance that dissolves the solute particles during the formation of a solution.

Question 21

attracted to water

Answer 21

hydrophilic

Question 22

resists water

Answer 22

hydrophobic

Question 23

Differentiate between acids and bases in terms of whether a substance adds H+ to solution or removes it.

Answer 23

the difference between acids and bases is that acids donate protons and bases accept protons. When a proton—a hydrogen ion—from an acid is accepted by a hydroxide ion from a base, the two ions join together and form a molecule of water.

Question 24

How does the fact that water is polar give it the ability to hold ions apart?

Answer 24

it can dissolve ionic substances

Question 25

If HCl dissociates in water to H+ and Cl-; is it an acid or a base?

Answer 25

Acid

Question 26

If a substance has a pH of 9 is it an acid or a base?

Answer 26

base

Question 27

What pH value is neutral (not an acid or base)?

Answer 27

7

Question 28

What does a buffer do?

Answer 28

A buffer is any substance that tends to minimize the changes in pH that might otherwise occur when an acid or base is added to a solution.

Question 29

molecules that contain carbon and other elements held together by covalent bonds.

Answer 29

Organic molecules

Question 30

large molecules built up from smaller subunits

Answer 30

Macromolecules

Question 31

Which type of chemical reactions between macromolecules joins them together or breaks them apart? (Hydrolysis or Dehydration Synthesis)

Answer 31

Dehydration builds and hydrolysis breaks down

Question 32

What are the four classes of organic molecules?

Answer 32

proteins, carbohydrates, lipids, and nucleic acids.

Question 33

Differentiate between monosaccharides, Disaccharides, Oligosaccharides and Polysaccharides.

Answer 33

When two units of monosaccharides are joint to form a complex it is called disaccharides, while 3-10 complexed units are termed as oligosaccharides and 11 or more units joined together are called as polysaccharides.

Question 34

Which of the terms describes glucose? starch? glycogen? (the ides)

Answer 34

Glucose is a monosaccharide starch and glycogen are polysacharides

Question 35

What type of chemical reaction bonds glucose molecules together to form glycogen? (Hydolysis or Dehydration Synthesis)

Answer 35

dehydration

Question 36

Describe the characteristics of lipids.

Answer 36

For biology, the most important physical characteristic of the class of organic molecules called lipids is that they are relatively insoluble, meaning they do not dissolve in water. The most important subclasses of lipids in your body are triglycerides, phospholipids, and steroids.

Question 37

Are lipids hydrophillic or hydrophobic?

Answer 37

hydrophobic

Question 38

Differentiate between Triglycerides and Fatty acids.

Answer 38

Triglycerides, also called neutral fats or just fats, are synthesized from a molecule of glycerol and three fatty acids (Figure 2.16a). Fatty acids are chains of hydrocarbons (usually about 16 to 18 carbons long) that end in a group of atoms known as a carboxyl group (HO¬C==O). Fats vary in the length of their fatty acid tails and

Question 39

Differentiate between saturated and unsaturated fats.

Answer 39

Saturated fats have a full complement of two hydrogen atoms for each carbon in their tails (Figure 2.16b). In saturated fats, the tails are fairly straight, allowing them to pack closely together. As a result, saturated fats are generally solid at room temperature Unsaturated fats, also called oils, have fewer than two hydrogen atoms on one or more of the carbon atoms in the tails (Figure 2.16c). As a result, double bonds form between adjacent carbons, putting kinks in the tails and preventing the fats from associating closely together. Consequently, unsaturated fats (oils) are generally liquid at room temperature.

Question 40

a modified form of lipid. They are the primary structural component of cell membranes.

Answer 40

Phospholipids

Question 41

Which portion of a phospholipid orients toward the inter or extracellular water? (Polar phosphate head or Non-polar fatty acid tails)

Answer 41

The polar phosphate head

Question 42

Know that steroids such as cholesterol, estrogen, and testosterone are

Answer 42

lipids

Question 43

Describe the relationship between proteins and amino acids.

Answer 43

Proteins are macromolecules constructed from long strings of single units called amino acids

Question 44

Primary structure.

Answer 44

The primary structure of a protein is represented by its amino acid sequence. In writing, each amino acid is indicated by a three-letter code

Question 45

Secondary structure.

Answer 45

Secondary structure. The secondary structure describes how the chain of amino acids is oriented in space. A common secondary structure of proteins is an alpha helix. An alpha helix is a right-hand spiral that is stabilized by hydrogen bonds between amino acids at regular intervals.

Question 46

Tertiary structure.

Answer 46

Tertiary structure, the third level, refers to how the protein twists and folds to form a three-dimensional shape.

Question 47

Quaternary structure

Answer 47

The quaternary (fourth) structure of some proteins refers to how many polypeptide chains make up the protein

Question 48

A protein that acts as a biological catalyst to speed up a chemical reaction

Answer 48

an enzyme

Question 49

What does it mean to denature an enzyme?

Answer 49

Denaturation refers to permanent disruption of protein structure, leading to a loss of biological function

Question 50

How does denaturation relate to our need to maintain homeostasis?

Answer 50

Denaturing enzymes can disrupt homeostasis

Question 51

List two nucleic acids. (the code)

Answer 51

Dna and rna

Question 52

What is the function of DNA?

Answer 52

DNA contains the instructions for producing RNA

Question 53

What is the function of RNA?

Answer 53

RNA contains the instructions for producing proteins.

Question 54

What is the relationship between DNA and the proteins that we produce?

Answer 54

Functionally, DNA maintains the protein-encoding information, whereas RNA uses the information to enable the cell to synthesize the particular protein. a. 1 Differences between DNA and RNA Notes: DNA stores the genetic information, where as RNA uses the information to help the cell produces the protein.