Chapter 2

Question 1

Matter

Answer 1

• anything that takes up space and has mass
• made up of elements
• consists of chemical elements in pure form and in combinations called compounds

Question 2

Elements

Answer 2

substances that cannot be broken down to other substances by chemical reactions

Question 3

Structure

Answer 3

helps dictate the function

Question 4

Compound

Answer 4

• a substance consisting of two or more elements combined in a fixed ratio
• has characteristics different from those of its elements

Question 5

Calcium and life

Answer 5

• associates with calmodulin
  1) bones
  2) muscle contraction
  3) RBC development
  4) brain function –> learning and memory

Question 6

What four elements make up 96% of living matter?

-plus calcium

Answer 6

1) Oxygen (65%)
2) Carbon (18.5%)
3) Hydrogen (9.5%)
4) Nitrogen (3.3%)
Calcium (1.5%)
-about 25 of 92 elements are essential to life

Question 7

Hyperthyroidism
(goiter)
(thyroid growth)

Answer 7

• Thyroid produces Thyroxine hormone (T3 and T4) from iodine
• iodine deficiency causes the brain to secrete thyroid stimulating hormone (TSH)
• TSH will cause the thyroid gland to grow and secrete (more) hormones
• normally T3 and T4 will give negative feedback and tell the pituitary gland to slow down the production of TSH
• can cause vision problems, heart attack

Question 8

Pituitary Gland –> Thyroid –> Thyroxines (T3 and T4) –> growth, metabolism, body temp, vision, bone formation

Answer 8

• pituitary gland produces TSH
• Thyroid gland needs iodine to produce T3 and T4
• sometimes thyroid hormone is given to help

Question 9

an element’s properties depend on the…

Answer 9

• structure of its atoms

- each element consists of a certain kind of atom that is different from those of other elements

Question 10

Atom

Answer 10

the smallest unit of matter that still retains the properties of an element and are composed of even smaller parts called subatomic particles

Question 11

Subatomic Particles

Answer 11

Neutrons, Electrons, Protons

Question 12

Neutrons

Answer 12

• subatomic particle that has no electrical charge

- found in the atomic nucleus

Question 13

Electrons

Answer 13

• subatomic particle that is negatively charged

- surround the nucleus in a “cloud”

Question 14

Protons

Answer 14

• subatomic particle that is positively charged

- found in the atomic nucleus

Question 15

Atomic Number of an element

Answer 15

the number of protons and is unique to each element

• Atoms of the various elements may occur in different 1) forms and differ in 2) their number of subatomic particles.

Question 16

an atom’s electrons …

Answer 16

vary in the amount of (potential) energy they possess

Question 17

Energy

Answer 17

the capacity to do work

Question 18

Potential Energy

Answer 18

energy that matter possesses because of its location or structure

Question 19

Valence electrons

Answer 19

electrons in the outermost shell, or valance shell, and determine most of the chemical behavior of an atom

Question 20

Covalent Bond

Answer 20

• sharing of a pair of valence electrons with two elements and form a molecule
• polar and non polar
• i.e. water (H2O), methane (CH4)

Question 21

the formation and function of molecules depend on …

Answer 21

chemical bonding between atoms

Question 22

Molecules

Answer 22

consists of 2 or more atoms held together by covalent bonds

Question 23

Single bond

Answer 23

sharing of one pair of valence electrons

Question 24

Double bond

Answer 24

sharing of two pairs of valence electrons

Question 25

Polar covalent bond

Answer 25

the atoms have differing electronegativities (attraction for the shared electrons) - share the electrons unequally ("hogs" all the electrons/energy) - i.e. water

Question 26

Ionic bond

Answer 26

- atoms strip electrons away from their bonding partners | - electron transfer between two atoms create ions

Question 27

Ions

Answer 27

charged atoms

Question 28

Anion

Answer 28

negatively charged ion

Question 29

Cation

Answer 29

positively charged ion

Question 30

Nonpolar

Answer 30

- don't dissolve in water very well | - usually hydrophobic

Question 31

Ionic compounds

Answer 31

- attraction between anions and cations - often called salts - i.e. sodium chloride (NaCl)

Question 32

Hydrogen bonding

Answer 32

- weak chemical bond - forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom - intermolecular interaction (between 2 distinct molecules) - i.e. ammonia and water

Question 33

Van der Waals Interactions

Answer 33

- occur when transiently (temporary/short lived) positive and negative regions or "hot spots" of molecules that attract each other - partially positive or negative regions - collectively, such interactions can be strong, as between moleculres of a gecko's toe hairs and a wall surface - AKA London forces

Question 34

4 types of bonds

Answer 34

1) Covalent 2) Ionic 3) Hydrogen bonds 4) Van der Waals

Question 35

Weak chemical bonds

Answer 35

reinforce the shapes of large molecules and help molecules adhere to each other

Question 36

the precise shape of a molecule is ...

Answer 36

usually very important to its function in the living cell and is determined by the positions of its atoms' valence orbitals

Question 37

Molecular Shape

Answer 37

determines how biological molecules recognize and respond to one another with specificity

Question 38

Chemical reactions

Answer 38

convert reactants to products

Question 39

Chemical equilibrium

Answer 39

is reached when the forward and reverse reaction rates are equal

Question 40

Intramolecular Interactions

Answer 40

interactions within the same molecule

Question 41

Photosynthesis

Answer 41

example of chemical reaction - sunlight powers the conversation of CO2 and H2O --> glucose and oxygen 6 CO2+ 6 H2O --> C6H12O6 + 6 O2

Question 42

Glucose

Answer 42

C6 H12 O6

Question 43

Same structures have ...

Answer 43

similar functions i.e. endorphin and morphine