Biochemistry - Chemistry Review

Question 1

VOCAB: Atom

Answer 1

smallest chemical unit of matter

Question 2

What is an Atom made of?

Answer 2

the core of protons and neutrons surrounded by a cloud of electrons.

Question 3

VOCAB: Atomic Number (A.N.)

Answer 3

the number of protons or electrons in an atom

Question 4

VOCAB: Atomic Mass (A.M.)

Answer 4

the sum of protons and neutrons (Protons + Neutrons)

Question 5

VOCAB: Element

Answer 5

a substance that can not be separated into different substances by ordinary chemical methods

Question 6

VOCAB: Isotopes

Answer 6

Atoms of an element but…

• they contain a different number of neutrons
• so they differ in mass

Question 7

VOCAB: Oxidation (in bonding)

Answer 7

that one atom has lost electrons

Question 8

VOCAB: Reduction (in bonding)

Answer 8

that one atom has gained electrons

Question 9

What are the characteristics of an ionic bond?

Answer 9

• between metal and non-metal
• metlas lose electrons and become positive ions
• non-metals gain electrons and become negative ions

Question 10

VOCAB: Ions

Answer 10

charged atoms due to a loss or gain of electrons

• a loss would make a positive ion.
• a gain would make a negative ion.

Question 11

VOCAB: Ionic bonds

Answer 11

form due to an attraction by opposite electrical charges.

- negative attracted to positive

Question 12

VOCAB: Octet Rule

Answer 12

electrons try to make completed shells of 8 electrons.

-EXCEPTION: the first shell has only 2 electrons.

Question 13

What are the characteristics of a covalent bond?

Answer 13

• between non-metals

- usually very stable

Question 14

VOCAB: Covalent Bond

Answer 14

sharing of electrons to complete shells.

Question 15

VOCAB: Polar Covalent Bond

Answer 15

between two non-metals sharing electrons unequally

Question 16

What molecule is absolutely essential to all life?

Answer 16

Water

Question 17

Where does water get its properties from?

Answer 17

its Hydrogen-bonds

Question 18

What are the types of compounds that dissolve in water? what are they called?

Answer 18

• ionic and polar covalent

- hydrophilic (water-loving)

Question 19

What type of compound does not dissolve in water? What is that called?

Answer 19

• covalent

- hydrophobic (water-hating)

Question 20

Water is known as the ________ solvent.

Answer 20

Water is known as the UNIVERSAL solvent.

Question 21

Where did all life begin? So all organisms are “______ based”.

Answer 21

Water. So all living organisms are “WATER-bassed”.

Question 22

How do all organisms maintain water levels?

Answer 22

by adaptations

Question 23

What % of the human body is water?

Answer 23

60-70%

Question 24

Only substances ______ in _______ can enter cell membranes in our body.

Answer 24

Only substances DISSOLVED on WATER can enter cell membranes in our body.

Question 25

Water carries away _______ _______ from our cells and _______ excreted in liquid.

Answer 25

Water carries away DISSOLVED WASTES from our cells and WASTES excreted in liquid.

Question 26

How are ions formed in water?

Answer 26

when an ionic substance is dissolved in water.

Question 27

In the human body water and water-based solutions act as __________.

Answer 27

In the human body water and water-based solutions act as LUBRICANTS.

Question 28

In human bodies what does water regulate?

Answer 28

Temperature

Question 29

What protects our brains against shock?

Answer 29

a watery layer

Question 30

Sense organs like our eyes and ears require _____ to function.

Answer 30

Sense organs like our eyes and ears require WATER to function.

Question 31

Water is abundant throughout what sphere?

Answer 31

The biosphere - the entire earth's surface that supports life.

Question 32

Water has a _____ freezing point and a _____ boiling point. Why?

Answer 32

Water has a LOW freezing point and a HIGH boiling point. | Because of its Hydrogen Bonds

Question 33

Why does the ocean maintain a basically constant temperature?

Answer 33

Because water absorbs much heat before it warms and releases much heat before it cools.

Question 34

Water has high COHESIVENSS, what does this mean? What does this make water good at?

Answer 34

water molecules tend to cling together and draw dissolved substances along with them. Make water a good transporter.

Question 35

Liquid water is ______ dense than ice.

Answer 35

Liquid water is MORE dense than ice.

Question 36

Water dissolves other _____ molecules.

Answer 36

Water dissolves other POLAR molecules.

Question 37

VOCAB: Acids

Answer 37

compounds that dissociate in water and release H(+) ions

Question 38

VOCAB: Bases

Answer 38

are compounds that dissociate in water and release OH(-) ions

Question 39

VOCAB: pH | - what does it measure, what is the scale

Answer 39

potential of Hydrogen - is a measure of the concentration of hydrogen ions - scale ranges from 0-14

Question 40

Explain the pH scale.

Answer 40

- the lower the pH the more acidic the solution - less than 7 is acidic - lth higher the pH the more basic (or "alkaline") the solution. - higher than 7 is basic - ph 7 in neutral - pure water

Question 41

What is the formula used to calculate pH?

Answer 41

pH = -log(H[+]) Ex: pH=3 then (H[+])=10[-3]=0.001

Question 42

Why can the numbers in the pH scale be misleading?

Answer 42

because it is a logarithmic scale

Question 43

What does a logarithmic scale mean?

Answer 43

each number on the scale (pH) represents a difference in magnitude of 10. Ex: - pH 2 is ten times more acidic than pH 3 - ph 13 is 1000 times more basic than pH 10

Question 44

All living things need to maintain a _______ pH.

Answer 44

All living things need to maintain a CONSTANT pH.

Question 45

Why is ph so important in living organisms?

Answer 45

Because if pH changes it can cause the enzymes to "denature"(change shape)

Question 46

How do living cells keep pH constant?

Answer 46

Buffers

Question 47

VOCAB: Buffer

Answer 47

a chemical or combination of chemicals that can take up excess hydrogen ions(H[+]) or excess hydroxide ions(OH[-]).

Question 48

Are Buffers are a foolproof solution to pH imbalances?

Answer 48

No, they can be overwhelmed

Question 49

What are some(4) common Buffers in living systems?

Answer 49

- carbonic acid(H{2}CO{3}) - bicarbonate (HCO{3}[-]) - acetic acid (CH{3}COOH) - acetate ion (CH{3}COO[-])