Chapter 2- Chemical Basis Of Life Flashcards Preview

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

Electricity

The flow of electrons (energy)

1

Matter

Anything that takes up space and has mass

2

Mass

A measure of the amount of matter an object contains

****Stays the same regardless if changes in the objects position****

3

Weight

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

4

Trace elements

Elements required by life in very minute quantities

5

Ultratrace elements

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

6

Compound

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

Ex: NaCl (sodium chloride)

7

Molecule

2+ atoms

8

Atom

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

Atoms of the same element share similar chemical properties

9

Subatomic particles

Neutrons, Protons, electrons

10

Electrostatic charge

✔️Two opposites attract each other
✔️Positive attracts negative

11

What is unique about hydrogen

It has only one electron and one proton, NO neutrons

12

Atomic nucleus

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

Mass of 1 proton, one neutron= 1 Dalton

13

Where are electrons located

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

Atomic number

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

Mass number

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

Octet rule

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

17

In what shell do electrons have most energy

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

18

Chemical reactions always go to the _________________? energy state

Chemical reactions always go to the LOWEST energy state

19

Inert

NOT reactive
Outermost shell is naturally full; ALL gasses (noble gasses)

20

Isotopes

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

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

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

22

Radioactive isotope

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

Fixed half-life

23

What are two biological applications of radioactive isotopes

1. Dating geological strata (layers) and fossils

2. Radioactive tracers

24

Radioactive tracers

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

Octet rule

Rule that valence shell is complete when it contains 8 electrons

26

Chemical bond

Attractions that hold molecules together

27

Covalent bond

✔️Strongest bond
✔️Chemical bonds formed by sharing s pair of valence electrons

28

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

Tetravalent

29

Valence

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

30

Electronegative atom

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

EX: N2 and O2 !!!!!!

31

Dipole

Uneven distribution of the charge in a molecule

32

Hydrogen bond

✔️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

Why is DNA hard to unravel?

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

34

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

4

35

What holds DNA together?

Weak hydrogen bonds

adenine----> thymine
cytosine---> guanine

36

Ion

A charged atom or molecule

37

Ionic bond

✔️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

Chemical reactions

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

Matter cannot be created nor destroyed

39

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

....greater probability of a reaction

40

Completion in chemical reaction

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

41

Chemical equilibrium

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

Homogenous

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

43

Dissociation of water molecules

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

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

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

DENATURED ENZYME

45

When does the #H+ = #OH-?

At equilibrium (pure water)

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Brackets indicate

Molar concentration

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[H+] + [OH-] = ?

M?


1/10,000,000

M= 10-7 M

48

Acid

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

49

Caustic

Either extremely acidic or extremely alkaline; will burn you

50

Base

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

51

LEO the lion says GER stands for ?

Lose electrons= oxidation
Gain electrons= reduction

Anything that breaks down into a positive and a negative

52

Salt

Substance formed by the reaction between an acid and a base

53

[H+][OH-]= ?

1.0 * 10-14

54

In what pH range are most biological fluids?

6 to 8

55

Each pH unit represents a ________ difference (logarithmic scale)

Tenfold

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

56

Buffers

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

How do buffers work?

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

Polymer

Large molecule consisting of many identical or similar subunits connected together

Ex: protein consists of many amino acids

59

Monomer

Subunit or building block molecule of a polymer

Ex: amino acids are the monomers of the polymer protein

60

Macromolecule

Large organic (carbon-containing) polymer

61

What are the four classes of macromolecules in living organisms

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

62

Polymerization reactions

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

63

Condensation reactions

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

Hydrolysis

(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

Carbohydrates

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

66

Monosaccharides

Simple sugars that are monomers or building block molecules in CARBOHYDRATES

CH2O

Major nutrients for cells ; glucose is most common

67

Where do carbs store energy

In their chemical bonds and it is harvested by cellular respiration

68

How do we get energy out of glucose?

Cellular respiration

69

Glycosidic linkage

Covalent bond formed by a condensation reaction between two sugar monomers

70

Preferential order of utilization

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

71

Polysaccharides

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

What's the most common storage polysaccharide in animals?

Glycogen

Glucose polymer in animals stored in muscle and liver

73

Where is glycogen stored in humans?

The liver and muscles

74

Lipids

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

75

What are the 3 important groups of lipids

Fats
Phospholipids
Steroids

76

What are fats composed of?

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

Affinity

Attraction towards

78

Fats

(Tail)

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

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ester linkage

Bond formed between a hydroxyl group and a carboxyl group

80

Characteristics of fat:

✔️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

Saturated fat

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

82

Unsaturated fat

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

83

What are 4 useful functions of fats?

✔️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

Phospholipids

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

85

How do phospholipids differ from fat?

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

86

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

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

Steroids

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

Ex: cholesterol is important steroid

88

Cholesterol

Very important steroid

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

89

Fluid- mosaic

Characteristic of cell membrane to move

Fluid- move all around
Mosaic- all different components

90

Protein

Polymer of amino acids

91

Structure of amino acids

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

92

Peptide

2+ amino acids

93

Peptide bond

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

94

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

20

95

What are the four levels of protein structure?

Primary structure
Secondary structure
Tertiary structure
Quaternary structure

96

Primary structure

The order of the amino acids in a peptide

97

Secondary structure

Coiled or FOLDED shape held together by hydrogen bonds

98

Tertiary structure

Further bending and folding

99

Quaternary structure

Between 2+ peptide chains

100

Will protein dissolve in water? Why/why not?

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

Protein conformation

✔️Overall protein shape
✔️Cannot function properly if shape is altered

102

Denatured protein

An unraveled or destroyed protein

Occurs when heat or changes in pH change protein shape

103

What are 6 functions of protein?

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