Week 4: Cellular Biology

Question 1

Element

Answer 1

simplest form of matter to have unique chemical properties

Question 2

Atomic Number

Answer 2

number of protons in its nucleus

Elements arranged by atomic number

Question 3

Electrolytes

Answer 3

mineral salts needed for nerve and muscle function

Question 4

Minerals

Answer 4

• inorganic elements extracted from soil by plants and passed up food chain to humans; Example: Ca, P, Cl, Mg,K, etc.
• about 4% of body weight
• important for body structure ie. Ca crystals in teeth, bones, etc.
• important for body structure

Question 5

Nucleus

Answer 5

Center of atom; made up of protons & neutrons

Question 6

Protons

Answer 6

Single + charge; mass = 1 amu

Question 7

Neutrons

Answer 7

No charge; mass= 1 amu

Question 8

Atomic Mass

Answer 8

Sum of protons & neutrons; accounts for the fact that an element is a mixture of isotopes & is close to the mass of the most abundant isotope.

Question 9

Eletrons

Answer 9

Single - charge; very little mass

Question 10

Valence Electrons

Answer 10

orbit the most outermost shell & determine chemical bonding properties of an atom

Question 11

Isotopes

Answer 11

varieties of an element that differ only in the number of neutrons; isotopes of an element are chemically similar because they have the same number of valence electrons

Question 12

Matter

Answer 12

anything that occupies space and has mass

Question 13

Energy

Answer 13

the ability to do work

Question 14

96% of body is made up of these elements

Answer 14

4: carbon, oxygen, hydrogen, and nitrogen

Question 15

Atoms

Answer 15

Building blocks of elements

Question 16

Radioisotope

Answer 16

• heavy isotope
• tends to be unstable
• Decomposes to more stable isotope

Question 17

Radioactivity

Answer 17

process of spontaneous atomic decay

Question 18

Molecule

Answer 18

two or more like atoms combined chemically

Question 19

Compound

Answer 19

two or more different atoms combined chemically

Question 20

Atoms formed with

Answer 20

Chemical Bonds

Question 21

How do atoms dissociate?

Answer 21

Breaking of chemical bonds

Question 22

Electron Shells

Answer 22

-electrons occupy energy levels
-Electrons closest to the nucleus are most strongly attracted
-Each shell has distinct properties:
The number of electrons has an upper limit
Shells closest to the nucleus fill first

Question 23

Which electrons are involved in bonding?

Answer 23

• Bonding involves interactions between electrons in the outer shell (valence shell)
• Full valence shells do not form bonds

Question 24

Inert Elements

Answer 24

Atoms are stable (inert) when the outermost shell is complete

Question 25

Electron Shell Capacity

Answer 25

Shell 1 can hold a maximum of 2 electrons Shell 2 can hold a maximum of 8 electrons Shell 3 can hold a maximum of 18 electrons

Question 26

Rule of Eights

Answer 26

Atoms are considered stable when their outermost orbital has 8 electrons The exception to this rule of eights is Shell 1, which can only hold 2 electrons

Question 27

How atoms reach stable state ?

Answer 27

Atoms will gain, lose, or share electrons to complete their outermost orbitals and reach a stable state

Question 28

Chemically inert element exampls

Answer 28

Hydrogen: 2 electrons; Neon= 10 electrons (2 in the inner shell, 8 in the second electron shell)

Question 29

Reactive Elements

Answer 29

-Valence Shells are not full and are unstable Tend to gain, lose, or share electrons Allow for bond formation, which produces stable valence

Question 30

Types of bonds

Answer 30

1.ionic 2. covalent 3.hydrogen 4.

Question 31

Ionic Bonds

Answer 31

Form when electrons are completely transferred from one atom to another

Question 32

Ions

Answer 32

Charged Particles: anions (-) & cations (+) - Either donate or accept electrons

Question 33

Anions

Answer 33

Negative Charge

Question 34

Cations

Answer 34

Positive Charge

Question 35

Covalent Bonds

Answer 35

- Atoms become stable through shared electrons - Single covalent bonds share one pair of electrons - Double covalent bonds share two pairs of electrons

Question 36

Single Covalent Bond Example

Answer 36

H2, CH4

Question 37

Double Covalent Bond Example

Answer 37

O2

Question 38

Polarity

Answer 38

Covalently bonded molecules - Some are non-polar: Electrically neutral as a molecule - Some are polar: Have a positive and negative side

Question 39

Non-polar bond examples

Answer 39

CO2

Question 40

Polar bond examples

Answer 40

H20

Question 41

Hydrogen Bonds

Answer 41

- Weak chemical bonds - Hydrogen is attracted to the negative portion of polar molecule - Provides attraction between molecules

Question 42

Synthesis Reaction

Answer 42

A+B => AB - Atoms or molecules combine - Energy is absorbed for bond formation

Question 43

Decomposition reaction

Answer 43

AB->A + B - Molecule is broken down - Chemical energy is released

Question 44

Synthesis Reaction example

Answer 44

Amino acids -> protein molecule

Question 45

Decomposition Reaction

Answer 45

Glycogen-> glucose units

Question 46

Exchange Reaction

Answer 46

AB + C--> AC + B - Involves both synthesis and decomposition reactions - Switch is made between molecule parts and different molecules are made

Question 47

Exchange Reaction Example

Answer 47

Glucose + ATP --> Glucose Phosphate + ADP

Question 48

Organic Compounds

Answer 48

Contain carbon Most are covalently bonded Example: C6H12O6 (glucose)

Question 49

Inorganic compounds

Answer 49

Lack carbon Tend to be simpler compounds Example: H2O (water)

Question 50

Water Vital Properties

Answer 50

- High heat capacity - Polarity/solvent properties - Chemical reactivity - Cushioning **Most abundant inorganic compound

Question 51

Salts

Answer 51

- Easily dissociate into ions in the presence of water - Vital to many body functions - Include electrolytes which conduct electrical currents

Question 52

Acids

Answer 52

- Release hydrogen ions (H+) | - Are proton donors

Question 53

Bases

Answer 53

- Release hydroxyl ions (OH–) | - Are proton acceptors

Question 54

Neutralization reaction

Answer 54

Acids and bases react to form water and a salt

Question 55

pH

Answer 55

Measures relative concentration of hydrogen ions pH 7 = neutral pH below 7 = acidic pH above 7 = basic

Question 56

Buffers

Answer 56

chemicals that can regulate pH change