CHAPTER 2 CHEMISTRY OF LIFE Flashcards

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1
Q

MATTER

A

is anything that takes up space and has mass. It is helpful to remember that matter can exist in a number of forms, including as a solid, gas, liquid, or plasma.

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2
Q

Elements

A

cannot be broken down by chemical means. A pure substance of one kind of atom

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3
Q

Atoms

A

the smallest unit of an element that still retains the chemical and physical properties of the element.

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4
Q

How do atoms of different elements differ?

A

in the number of protons & neutrons they have

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5
Q

Parts of an Atom

A

Protons: positive charge
Neutrons: neutral charge
Electrons: negative charge

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6
Q

Why does an atom always have the same number of protons and electrons ?

A

so the charge on an atom is neutral

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7
Q

Structure of an atom

A

the nucleus is a central core containing protons and neutrons
the electrons are arranged in orbitals around the nucleus

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8
Q

common elements in inorganic molecules

A
K = Potassium 
Na = Sodium 
Fe = Iron
Cl = Chlorine 
Ca= Calcium
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9
Q

common elements in organic molecules

A
C = Carbon 
H =Hydrogen 
O =Oxygen 
N = Nitrogen 
P =Phosphorus
S = sulfur
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10
Q

An Atom will always contain the same number of …

A

protons & electrons

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11
Q

Isotopes

A

atoms of the same atomic number but have different atomic mass because the number of neutrons differ

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12
Q

Radioactive isotopes

A

are useful in dating old objects

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13
Q

Radiation

A

can be harmful by damaging cells and DNA and or causing cancer

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14
Q

Ions

A

atoms that have gained or lost electrons; this makes them either positively or negatively charged particles

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15
Q

Ionic bond

A

occurs between ions of the opposite charge

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16
Q

Covalent bond

A

when two atoms share electrons. Strongest bond

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17
Q

Hydrogen bond

A

forms between slightly positive (partial + charge) and slightly negative (partial – charge) . usually occur between a hydrogen and either an oxygen or a nitrogen atom, which is sometimes called an electronegative atom. The weakest bond.

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18
Q

Electronegative atom

A

tends to attract electrons

The most common in biological atoms are O (oxygen) & N (nitrogen)

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19
Q

solute

A

substance dissolved in a liquid

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20
Q

solvent

A

the liquid the substance is dissolved in

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21
Q

solution

A

a liquid (solvent) containing dissolved substances (solute)

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22
Q

aqueous solution

A

a solution made with water

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23
Q

Name 3 properties that make water special

A
  • liquid at room temperature
  • liquid water does not change temperature quickly
  • high heat of vaporization
  • frozen water is less dense than liquid water
  • molecules of water cling together due to hydrogen bonds
24
Q

What bond holds water molecules together?

A

Hydrogen bond

25
Q

Hydrophobic

A

molecules that cannot attract water; tend to attract to other polar molecules

26
Q

Hydrophilic

A

molecules that can attract water; tend to attract to nonpolar molecules. When ions and molecules disperse in water, they move about and collide, allowing reactions to occur.

27
Q

pH Scale

A

a measure of how acidic or basic a substance is
A measure of hydrogen ion concentration
A working scale between 0 & 14

pure water has a neutral pH = pH7

28
Q

acids

A

are substances that release H+ when they dissociate into ions
Example: HCL -> H+ CL-

the higher the H + the lower the pH
the pH of acidic solutions: below 7 pH

29
Q

bases

A

are substances that release OH - when they dissociate into ions
Example: NaOH -> Na+ + OH-

the lower the H+ the higher the pH
the pH of basic or alkaline solutions: above 7 pH

30
Q

buffers

A
  • A mixture of acid & base that helps maintain a constant pH
  • pH of blood 7.4 = BASE
  • Carbonic acid in blood acts as a …
31
Q

Macromolecules

A
  • are large organic molecules made of smaller organic molecules (subunits).
  • Food molecules
  • Some molecules act as hormones
  • Nucleic acids are involved in genetics & inheritance
32
Q

Dehydration Synthesis Reaction

A

-Purpose: the removal of water that allows subunits to link together to make larger molecules
-Structure: 2 monomers are connected together with a covalent bond
-Is a longer or shorter molecule made?
SMALL TO LARGE
-Is a molecule of water used up or is a molecule of water made at the end of the reaction?
PRODUCED OR MADE

33
Q

Hydrolysis Reaction

A

-Purpose: the addition of water that breaks large molecules into their smaller subunits
-Structure: the covalent bond between 2 subunits is broken
-Is a longer or shorter molecule made?
LARGE TO SMALL
-Is a molecule of water used up or is a molecule of water made at the end of the reaction?
USED UP

34
Q

Carbohydrates

A

-General formula: CH 2 0 or H-C-OH
-Simple carbohydrate: made of 1 or 2 sugar units
Function: food
-Monosaccharides: simple sugars, or glucose
Provide immediate energy
Provide energy for the cells in the body
-Disaccharides: 2 sugars connected by a covalent bond that is called maltose
Provide immediate energy

35
Q

Polysaccharides:

A
  • Complex carbohydrates
  • Long polymer (chain) made of sugar subunits
  • These subunits can be branched or unbranched
36
Q

A type of polysaccarides: Storage

A
  • stored form of energy in the cell = stored food
  • These compounds are easily broken down when the cell needs sugar for energy
  • Ex: starch- plant cells, glycogen- animal cells
37
Q

A type of polysaccarides: Structural

A
  • Structural component of the cell not food
  • These compounds are very stable, so they cannot be broken down
  • Cellulose: cell wall of plants (fiber)
  • Chitin: shell of insects & crustaceans
38
Q

function of carbohydrates

A
  • Short- term energy = sugar
  • Stored form of energy: Polysaccharides, such as starch or glycogen
  • Form structures within the cell wall ( cell wall = cellulose)
39
Q

fiber

A
  • Nondigestible carbohydrates from plants

- Ex: beans, peas, nuts, fruits, vegetables

40
Q

2 types of fiber

A

Soluble:

  • Combines with cholesterol in the small intestine and prevents it from being absorbed
  • This may protect against heart disease

Insoluble:

  • Promotes water absorption
  • Prevents constipation: extra bulk stimulates movements of small intestine & extra water makes stool easier to pass
41
Q

Lipids

A

-Contain the elements: CHO some P
Functions:
-Molecules that do not dissolve in water = Hydrophobic
-Used as energy molecules = food
-Found in cell membranes
-Found as fats and oils (triglycerides), phospholipids and steroids

42
Q

3 types of lipids

A
-Triglycerides: fats & oils / fatty acids combine to form this type of lipid 
Function: 
Long term energy storage 
insulation against heat lost 
protective cushioning around organs 
-Phospholipids: orient themselves with the polar heads facing watery solutions because they contain both hydrophilic and hydrophobic regions. Contain 2 fatty acids and 1 phosphate group 
Function:
the main component of membranes, which are phospholipid bilayer.
Structure:
Glycerol
2 Fatty Acids
Phosphate group
Polar headgroup

-Steroids: different types of steroids molecules are distinguished by the type(s) of functional group(s) attached to the carbon rings
structure:
four fused carbon rings
3 Examples: cholesterol, cortisol, and sex hormones
Function:
Many steroids are hormones. Ex. Cortisol, testosterone, estrogen.
Hormones are chemical signals that control many processes in the body.
Some steroids have a structural function.
Cholesterol is in cell membranes

43
Q

How are phospholipids arranged in a membrane?

A
  • The polar heads are soluble in water, so are on the surface of the membrane
  • The nonpolar tails are not soluble in water, so are in the middle of the membrane
44
Q

Fats

A
  • Usually animal origin
  • Solid at room temperature

Function:
•long-term energy storage
•insulation from heat loss
•cushion for organs

45
Q

Oils

A

Usually plant origin

Liquid at room temperature

46
Q

saturated and unsaturated fats

A

Saturated fats are solid at room temperature because all of the fatty acids in the triglyceride have only single bonds. These bonds make the fatty acid molecule straight and easy to pack together. ex: butter
Unsaturated fats are liquid at room temperature because at least one of the fatty acids in the triglyceride has at least one double or triple bond. This kind of bond puts a bend or kink in the fatty acid molecule and makes it harder to pack together. ex: oils

47
Q

saturated fats and your heart

A

Saturated fats contribute to: Atherosclerosis
In Atherosclerosis fatty deposits called plaques form on the inside of blood vessels. This makes the blood vessels narrower, which reduces blood flow and o2 supply

48
Q

Trans fat

A

How is trans fat made?
partially hydrogenating vegetable oil
Are trans fats healthy? NO

49
Q

Polyunsaturated fat

A

-What is polyunsaturated fat?
contain many double bonds in their Fatty Acids
-Example: corn, canola, and safflower oil (best)
-Is polyunsaturated fat healthy? YES

50
Q

Which of the fats discussed is the healthiest? Which fat is the unhealthiest?

A

healthiest: polyunsaturated fat
unhealthiest: trans fat

51
Q

Review of Lipid Function in the Body

A

-Membrane Structure: phospholipids, cholesterol (a steroid)
•Energy Store: triglycerides (fats & oils)
•Hormones: steroids

52
Q

Proteins

A

-Composed of the elements: CHONS
-proteins are made of subunits called amino acids
functions:
-Enzymes: speed up chemical reactions
-Structure
-Transport
-Hormones Ex. insulin
-Antibodies

53
Q

Levels of Protein Structure

A

Primary Structure: the sequence of amino acids connected by peptide bonds
Secondary Structure: localized folding of the amino acid chain
Tertiary Structure: amino acid chain continues to fold up into its final 3D shape
All proteins have structures 1-3
Quaternary Structure: when one protein subunit binds to another subunit. Only found in proteins that have more than 1 subunit.

54
Q

Denaturation

A

When proteins are denatured they: unfold and no longer work properly

Chemical Cause: bonds involved in 3D structure are broken and protein loses its shape
Physical Cause: high temperature, change in pH, high salt

55
Q

Nucleic Acids

A

Contain the elements: CHONP
Nucleic acids are made of subunits called nucleotides
Function:
Contains Info in cell used to make proteins
Examples of Nucleic Acids:
RNA & DNA

56
Q

Structure of a Nucleotide

A

phosphate, pentose sugar, nitrogen-containing base

RNA: contains the sugar ribose in ribonucleotides (NTPs)
DNA: contains the sugar deoxyribose in deoxyribonucleotides