Chapter 2 - The Nature of Life

Question 1

Attributes of living organisms

Answer 1

Composition and structure
Growth
Reproduction
Response to stimuli
Metabolism
Movement
Complexity and organization
Adaption to the environment

Question 3

Bonds and ions

Answer 3

Covalent bonds
Ionic bonds
Hydrogen bonds

Question 4

Growth

Answer 4

Increase in mass, usually accompanied by an increase in volume.

Question 5

Nucleus

Answer 5

Part of atom containing protons and neutrons.

Question 6

Protons

Answer 6

• Positively-charged part of an atom
• Has mass
• Affects the path of electrons around the nucleus

Question 7

Atom

Answer 7

The smallest stable subdivision of an element that can exist

Question 8

Reproduction

Answer 8

Offspring always resemble the parents more than other individuals of the same kind. (see chapter 13)

Question 9

Orbital

Answer 9

• Region occupied by electrons around the nucleus

* A volume of space in which a given electron occurs 90% of the time.

Question 10

Isotopes

Answer 10

Variations of elements with slightly different numbers of neutrons in the atoms, resulting in different weights but all forms behaving alike chemically

Question 11

Electrons

Answer 11

• Negative charges that whirl around the nucleus.

Question 12

Valence

Answer 12

The combining capacity of an atom or ion based on electron number.

Question 13

Covalent bonds

Answer 13

Form when two atoms complete their outermost energy level by sharing a pair of electrons in the outermost orbital. They hold two or more atomic nuclei together and travel between them.

Question 14

Neutrons

Answer 14

• Part of an atom with no electrical charge

* Has mass

Question 15

Hydrogen bonds

Answer 15

Form when positively charged hydrogen atoms in polar molecules are attracted to negatively charged atoms in other polar molecules.

Question 16

Acids

Answer 16

Chemicals that release hydrogen ions (H+) in water

Question 17

Ionic bonds

Answer 17

Molecules that lose or gain electrons and become either positively or negatively charged particles.

Question 18

Compound

Answer 18

A substance where 2 or more elements are united in a definite ratio by chemical bonds.

Question 19

Molecule

Answer 19

• The smallest unit of an element or compound retaining its own identity.
• 2 or more atoms bound together

Question 20

pH

Answer 20

• Scale (0-14) to measure acidity or alkalinity
• Each unit (0-14) represents a tenfold change in H+ concentration.
• Pure water is 7/neutral, number of H+ and OH- is the same.

Question 21

Thermodynamics

Answer 21

Study of energy and its conversions from one form to another.

Question 22

Bases (alkaline compounds)

Answer 22

• Feel slippery or soapy

* Compounds that accept H+ ions.

Question 23

Second law of thermodynamics

Answer 23

Energy contained within a system and is converted from one form to another, flows from a high to a low state (heat flows from hot objects to cool surfaces).

Question 24

Polymers

Answer 24

“Many units”

- formed when two or more monomers bond together

Question 25

First law of thermodynamics

Answer 25

Energy is constant – it cannot be gained or lost – but can be converted from one form to another. Forms include: chemical, electrical, heat, and light.

Question 26

Monomers

Answer 26

"Single unit" | - smaller cell components that bond through dehydration synthesis to create polymers

Question 27

Characteristics of matter

Answer 27

1. Occupies space 2. Has mass (weight) 3. Composed of elements

Question 28

Monosaccharides

Answer 28

- a kind of carbohydrate (polymer) - Simple sugars with backbones of 3-7 carbon atoms - includes glucose, fructose

Question 29

Disaccharides

Answer 29

- a kind of carbohydrate (polymer) - formed when two or more monosaccharides bond via dehydration synthesis - includes sucrose (glucose+fructose)

Question 30

Carbohydrates

Answer 30

- One of the most important classes of polymers. - The most abundant organic compound in nature. - Includes sugars, starches - CH2O

Question 31

Cellulose

Answer 31

Chief structural polymer in cell walls (3000-10000 chains of glucose molecules)

Question 32

Lipids

Answer 32

- Fatty or oily substances insoluble in water because contain no polarized components - store twice as much energy as carbohydrates - important to long-term energy reserves of cells - broken down by hydrolosis

Question 33

Polysaccharides

Answer 33

- A kind of carbohydrate (polymer) - Formed when more than 2 monosaccharides bond together - example is starch, a string of glucose molecules that have bonded, each giving up a molecule of water

Question 34

Proteins

Answer 34

- second only to cellulose in making up dry weight of plant cells - regulate chemical reactions in cells - usually very large molecules of one or more polypeptide chains

Question 35

Polypeptides

Answer 35

Chains of amino acids

Question 36

Amino acids

Answer 36

a

Question 37

Peptide bonds

Answer 37

- Link together amino acids through covalent bonds

Question 38

Storage proteins

Answer 38

a

Question 39

Growth

Answer 39

* An increase in mass, usually accompanied by an increase in volume. * Results from the production of new cells and includes variation in form. * Controlled by a plant's genetic makeup and the environment in which its grown.

Question 40

Enzymes

Answer 40

a

Question 41

Nucleic acids

Answer 41

a

Question 42

Nucleotides

Answer 42

a

Question 43

Response to Stimuli

Answer 43

Plants respond to injury and other stimuli, such as light, temperature, and gravity.

Question 44

Metabolism

Answer 44

The collective product of all the biochemical reactions taking place within an organism. Most important activities: respiration, photosynthesis, digestion, assimilation.

Question 45

Movement

Answer 45

Most plants movements are slow, imperceptible, and mostly related to growth. Not confined to the organism as a whole, but occurs at the cellular level.

Question 46

Complexity of an Organization

Answer 46

Cells contain large numbers of molecules (more than 1 trillion molecules in a single cell). Numbers of molecule types can be in the millions for flowering plants and other large objects.

Question 47

Reproduction

Answer 47

Offspring always resemble parents more than they do other individuals of the same kind.

Question 48

Genes

Answer 48

a

Question 49

Organic compounds

Answer 49

Have a "backbone" of carbon atoms

Question 50

Inorganic compounds

Answer 50

Have no carbon atoms (except carbon dioxide CO2 and sodium bicarbonate NaHCO3)

Question 51

Dehydration synthesis

Answer 51

Bonds two monomers together when H+ is removed from one monomer and hydroxyl OH- removed from the other creating an electrical attraction - also known as a condensation reaction

Question 52

Hydrolysis

Answer 52

Opposite of dehydration synthesis, when H+ from water attaches to one monomer and OH- to another, resulting in energy being released

Question 53

Isomer

Answer 53

Molecules with the same numbers and kind of atoms but different in structure and shape

Question 54

Sucrose

Answer 54

The form in which sugar is transported through plants

Question 55

Waxes

Answer 55

- A kind of lipid - usually embedded in cutin or suberin (also lipids) on leaf surfaces - provide waterproofing, prevent water loss, protection against insects and microorganisms

Question 56

Phospholipids

Answer 56

- a kind of lipid - constructed chemically like fats but with some polarized ions - important component in membranes in living organisms

Question 57

Adaptation to the Environment

Answer 57

Response to air, water, light, soil, genetic fitness.

Question 58

Energy

Answer 58

The ability or capacity to do work or to produce a change is motion or matter.