Chapter 2- Chemical Basis Of Life Flashcards Preview

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Flashcards in Chapter 2- Chemical Basis Of Life Deck (104)
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0
Q

Matter

A

Anything that takes up space and has mass

1
Q

Electricity

A

The flow of electrons (energy)

2
Q

Mass

A

A measure of the amount of matter an object contains

Stays the same regardless if changes in the objects position

3
Q

Weight

A

The measure of how strongly an object is pulled by earths gravity and it varies with distance from earths center

4
Q

Trace elements

A

Elements required by life in very minute quantities

5
Q

Ultratrace elements

A

Element required by organisms in extremely minute quantities but are TOXIC at high levels (arsenic- Ar)

6
Q

Compound

A

A pure substance composed of 2+ different elements combined in a fixed ratio (✔️molecule)

Ex: NaCl (sodium chloride)

7
Q

Molecule

A

2+ atoms

8
Q

Atom

A

Smallest possible unit of matter that retains chemical/physical properties of its element

Atoms of the same element share similar chemical properties

9
Q

Subatomic particles

A

Neutrons, Protons, electrons

10
Q

Electrostatic charge

A

✔️Two opposites attract each other

✔️Positive attracts negative

11
Q

What is unique about hydrogen

A

It has only one electron and one proton, NO neutrons

12
Q

Atomic nucleus

A

Where protons and neutrons are found; where mass of entire atoms is measured

Mass of 1 proton, one neutron= 1 Dalton

13
Q

Where are electrons located

A

Orbit around the nucleus; held together by electrostatic attraction to positively charged nucleus

Mass so small, it’s not used to calculate atomic mass

14
Q

Atomic number

A

DETERMINES the atom (unique to each)

Number of protons in an atom

All atoms of an element have the same atomic number (subscripts to the of the elements written symbol)

15
Q

Mass number

A

Number of protons and neutrons in an atom (one of each has mass of approx 1 dalton)

Superscript to left or an elements symbol

16
Q

Octet rule

A

1st shell- max 2 electrons
2nd shell- max 8 electrons
3rd shell- max 8 electrons

17
Q

In what shell do electrons have most energy

A

The further out the shell, the more energy the electrons have because they aren’t being pulled into positively charged nucleus as strongly

18
Q

Chemical reactions always go to the _________________? energy state

A

Chemical reactions always go to the LOWEST energy state

19
Q

Inert

A

NOT reactive

Outermost shell is naturally full; ALL gasses (noble gasses)

20
Q

Isotopes

A

Atoms of an element that have the same atomic number but different mass number

Different number of NEUTRONS

Under natural conditions, elements occur as mixtures of isotopes

21
Q

Different isotopes of the same element react chemically in the ____________ way.

A

Different isotopes of the same element react chemically in the SAME way.

22
Q

Radioactive isotope

A

Unstable isotope in which the nucleus spontaneously decays emitting subatomic particles and/or energy as radioactivity

Fixed half-life

23
Q

What are two biological applications of radioactive isotopes

A
  1. Dating geological strata (layers) and fossils

2. Radioactive tracers

24
Q

Radioactive tracers

A

Trace steps of biochemical reaction or to determine the location of a particular substance within organism

Useful bc they chemically react like the stable isotopes and are easily detected at low concentrations

Diagnose disease

Cause or cure cancer

25
Q

Octet rule

A

Rule that valence shell is complete when it contains 8 electrons

26
Q

Chemical bond

A

Attractions that hold molecules together

27
Q

Covalent bond

A

✔️Strongest bond

✔️Chemical bonds formed by sharing s pair of valence electrons

28
Q

Carbon and silicon have 4 valence electrons, what is this called?

A

Tetravalent

29
Q

Valence

A

Bonding capacity of an atom which is the number of covalent bonds that must be formed to complete the outer shell

30
Q

Electronegative atom

A

The personality of some atoms to be attracted to electrons and pull them close to them!!

EX: N2 and O2 !!!!!!

31
Q

Dipole

A

Uneven distribution of the charge in a molecule

32
Q

Hydrogen bond

A

✔️Weak bond
✔️form between molecules or diff parts of a large molecule
✔️Bond formed by the charge attraction when HYDROGEN is COVALENTLY bonded to an ELECTRONEGATIVE atom and is attracted to another electronegative atom
✔️indicated by dotted line in structural formula

33
Q

Why is DNA hard to unravel?

A

Bc it has ALOT of weak hydrogen bonds which are strong when together bc there are so many

34
Q

How many hydrogen bonds can a water molecule form with neighboring water molecules?

A

4

35
Q

What holds DNA together?

A

Weak hydrogen bonds

adenine—-> thymine
cytosine—> guanine

36
Q

Ion

A

A charged atom or molecule

37
Q

Ionic bond

A

✔️Formed by the electrostatic attraction (positive—>neg.) after the complete transfer of an electron from a donor atom to an acceptor. (Acceptors attract electrons bc electronegative)

✔️strong bonds in crystals not in water (salt dissolves in water bc ionic bonds dissociate into ions

38
Q

Chemical reactions

A

Making and breaking chemical bonds leading to changes in composition of matter; reactants—> products

Matter cannot be created nor destroyed

39
Q

The relative concentration of reactants and products affects the reaction rate. The higher the concentration the ____________

A

….greater probability of a reaction

40
Q

Completion in chemical reaction

A

All reactants are converted to products. (Majority are reversible)

41
Q

Chemical equilibrium

A

The RATE of the forward reaction (speed/time) equals the RATE (speed/time) of the reverse reaction

Dynamic- reactions continuing in both directions.

Relative concentrations of reactants/products stay the same

42
Q

Homogenous

A

Particles in a mixture are all spread out throughout; mixed together

43
Q

Dissociation of water molecules

A

Occasionally, the hydrogen atom that is shared in a hydrogen bond between two water molecules, shifts from the oxygen atom to which its covalently bonded to the unshared orbitals of the oxygen atom to which its hydrogen bonded

H2O—–> OH+H

44
Q

What would happen if you took protein (slightly negative charge) and dumped it in acid?

A

The H+ ions (protons) will all pull the electrons toward them changing the shape of protein thus affecting its function

DENATURED ENZYME

45
Q

When does the #H+ = #OH-?

A

At equilibrium (pure water)

46
Q

Brackets indicate

A

Molar concentration

47
Q

[H+] + [OH-] = ?

M?

A

1/10,000,000

M= 10-7 M

48
Q

Acid

A

Substances that increase the [H+] of a solution; also removed [OH-] bc it combines with H+ to form H2O

49
Q

Caustic

A

Either extremely acidic or extremely alkaline; will burn you

50
Q

Base

A

Substances that reduce the relative H+ of a solution; may alternately increase OH-

51
Q

LEO the lion says GER stands for ?

A

Lose electrons= oxidation
Gain electrons= reduction

Anything that breaks down into a positive and a negative

52
Q

Salt

A

Substance formed by the reaction between an acid and a base

53
Q

[H+][OH-]= ?

A

1.0 * 10-14

54
Q

In what pH range are most biological fluids?

A

6 to 8

55
Q

Each pH unit represents a ________ difference (logarithmic scale)

A

Tenfold

Slight change in pH= large change in actual [H+]

56
Q

Buffers

A

Minimizing wide fluctuations in pH to help organisms maintain the Psh of body fluids within the narrow range necessary for life

Prevents sudden changes in pH

Ex: Bicarbonate (buffer in blood)

57
Q

How do buffers work?

A

They either donate H+ to the solution when they have been depleted or accept H+ from the solution when they are i know excess

58
Q

Polymer

A

Large molecule consisting of many identical or similar subunits connected together

Ex: protein consists of many amino acids

59
Q

Monomer

A

Subunit or building block molecule of a polymer

Ex: amino acids are the monomers of the polymer protein

60
Q

Macromolecule

A

Large organic (carbon-containing) polymer

61
Q

What are the four classes of macromolecules in living organisms

A

Carbohydrates
Lipids
Proteins
Nucleic acid (DNA,RNA, and ATP)

62
Q

Polymerization reactions

A

Chemical reactions that link 2+ small molecules to form molecules with repeating structural units (making a polymer)

63
Q

Condensation reactions

A

Mose polymerization reactions in living things !!!!

(Anabolism) Monomers are covalently linked, producing net removal of a water molecule for each covalent linkage

One monomer loses OH and another loses H

Requires energy

64
Q

Hydrolysis

A

(Catabolism)
A reactions process that breaks (splits) covalent bonds between monomers by the addition of water molecules

Hydrogen fro water bonds with one monomer and remaining OH from water bonds with adjacent monomer

Ex: digestive enzymes catalyze hydrolysis reactions which BREAK APART large food molecules into monomers that can be absorbed into the bloodstream

65
Q

Carbohydrates

A

Organic (must have carbons and hydrogen to be organic) molecules made of sugars and their polymers

66
Q

Monosaccharides

A

Simple sugars that are monomers or building block molecules in CARBOHYDRATES

CH2O

Major nutrients for cells ; glucose is most common

67
Q

Where do carbs store energy

A

In their chemical bonds and it is harvested by cellular respiration

68
Q

How do we get energy out of glucose?

A

Cellular respiration

69
Q

Glycosidic linkage

A

Covalent bond formed by a condensation reaction between two sugar monomers

70
Q

Preferential order of utilization

A

Body’s favorite order of what macros to use first for energy
Carbs –> protein –> fat

71
Q

Polysaccharides

A

Macromolecules that are polymers of a few hundred or thousand monosaccharides

Formed by linking monomers in enzyme-mediated condensation (joining by removing water) reactions

72
Q

What’s the most common storage polysaccharide in animals?

A

Glycogen

Glucose polymer in animals stored in muscle and liver

73
Q

Where is glycogen stored in humans?

A

The liver and muscles

74
Q

Lipids

A

Diverse group of organic compounds that are insoluble in water (hydrophobic) but will dissolve in non polar (like dissolves like) solvents

75
Q

What are the 3 important groups of lipids

A

Fats
Phospholipids
Steroids

76
Q

What are fats composed of?

A
Glycerol- a three-carbon alcohol
Fatty acid (carboxyl acid)- composer of a carboxyl group (COOH) head at one end and an attached hydrocarbon chain (tail)
77
Q

Affinity

A

Attraction towards

78
Q

Fats

A

(Tail)

Hydrocarbon chain (C-H)
Hydrophobic and not water soluble
79
Q

ester linkage

A

Bond formed between a hydroxyl group and a carboxyl group

80
Q

Characteristics of fat:

A

✔️Insoluble to water
✔️variation among fat molecules is the fatty acid composition
✔️fatty acids in a fat may all be the same or some (all) may differ
✔️ vary in length
✔️ vary in number and location of carbon to carbon double bonds

81
Q

Saturated fat

A

✔️No double bonds between carbons and fatty acid tail
✔️bonded to MAX number of hydrogens
✔️ solid at room temp
✔️most animal fats

82
Q

Unsaturated fat

A

✔️one+ double bonds between carbons in fatty acid tail
✔️liquid at room temp
✔️plant fats

83
Q

What are 4 useful functions of fats?

A

✔️energy storage (one gram stores twice as much energy as a gram of polysaccharide
✔️more compact fuel reservoir (store more energy for less weight than in plants)
✔️cushions vital organs (kidney)
✔️insulated against heat loss

84
Q

Phospholipids

A

Compounds with molecular building blocks of glycerol, 2 fatty acids, one phosphate group, usually an additional small chemical group attached to the phosphate

85
Q

How do phospholipids differ from fat?

A

The third carbon of glycerol is joined to a negatively charged phosphate group instead of another fatty acid

86
Q

How is a cell membrane’s phospholipid bilayer set up?

A

Has two layers of phospholipids. Each have a hydrophilic head polar head and two hydrophobic fatty acid nonpolar tails. The heads are facing outward toward extra|intra cellular areas and tails are facing inward

87
Q

Steroids

A

Lipids which have 4 fused carbon rings with various functional groups attached

Ex: cholesterol is important steroid

88
Q

Cholesterol

A

Very important steroid

✔️adds stability to cell membrane (adds viscosity (thickness) to membrane)
✔️precursor to many other steroids (sex hormones etc)

89
Q

Fluid- mosaic

A

Characteristic of cell membrane to move

Fluid- move all around
Mosaic- all different components

90
Q

Protein

A

Polymer of amino acids

91
Q

Structure of amino acids

A

Carboxyl end (COOH) and an amino acid end (NH2) as well as a variable R group

92
Q

Peptide

A

2+ amino acids

93
Q

Peptide bond

A

Formed between the amino group (NH2) of one amino acid to the carboxyl group (COOH) of the next

94
Q

How many kinds of amino acids are use in protein structure?

A

20

95
Q

What are the four levels of protein structure?

A

Primary structure
Secondary structure
Tertiary structure
Quaternary structure

96
Q

Primary structure

A

The order of the amino acids in a peptide

97
Q

Secondary structure

A

Coiled or FOLDED shape held together by hydrogen bonds

98
Q

Tertiary structure

A

Further bending and folding

99
Q

Quaternary structure

A

Between 2+ peptide chains

100
Q

Will protein dissolve in water? Why/why not?

A

Yes bc proteins is polar and water is polar. Like dissolves like. The protein will bend on itself until is bonds with hydrogen in H2O

101
Q

Protein conformation

A

✔️Overall protein shape

✔️Cannot function properly if shape is altered

102
Q

Denatured protein

A

An unraveled or destroyed protein

Occurs when heat or changes in pH change protein shape

103
Q

What are 6 functions of protein?

A
✔️structural components
✔️enzymes for catalysis 
✔️communication 
✔️membrane transport 
✔️cell recognition/protection
✔️movement