lecture 2 Flashcards
(115 cards)
1
Q
everything is made of ______
A
matter
2
Q
smallest unit of matter
A
atom
3
Q
molecules are … (2)
A
a group of atoms
connected by covalent bonds
4
Q
Compounds are … (3)
A
atoms connected by chemical bonds
in a fixed ratio
5
Q
chemical bonds (3)
A
ionic bonds
covalent bonds
hydrogen bonds
6
Q
covalent bond
A
when two atoms share one or more pairs of electrons
7
Q
ionic bond
A
when a metal transfers one or more electrons to a nonmetal.
or
when two ions are held together by opposite charges
8
Q
compound
A
a substance made of two or more different chemicals combined in a fixed ratio
9
Q
water is … (
A
held by a polar covalent bond
when there are multiple, they are held by hydrogen bonds through electronegativity
10
Q
water exhibits ______
what does it mean?
A
cohesion
molecules tend to stick to one another
11
Q
why is water good at moderating temperature?
A
water takes a long time to heat up because before the molecules can move (heat up), the hydrogen bonds keeping them in place must be broken
12
Q
why does water expand on freezing?
A
hydrogen bonds forces water into an orderly fashion called a lattice while freezing, making it less dense than water
13
Q
polar
A
a molecule with a charge on one side that is not canceled out
or
a molecule that is not symmetrical
14
Q
non polar
A
molecules with even charge distribution and symmetrical shape
15
Q
hydrophilic
A
water loving - phosphate group
16
Q
hydrophobic
A
water fearing - oil
17
Q
acid
A
a substance that increases the H+ concentration in water
18
Q
base
A
a substance that increases the concentration of OH- in water
19
Q
buffer
A
substances that minimize change in pH
20
Q
what pH must blood be kept between
A
7.35-7.45
21
Q
what happens when blood pH falls below 7.35 or above 7.45
A
below - blood acidosis
above - blood alkalosis
22
Q
what do organic molecules contain
A
carbon
23
Q
carbon skeleton
A
carbons connected by covalent bonds in a chain or ring
24
Q
functional groups
A
other atoms or molecules attaches to the carbon skeleton
25
hydroxyl
- part of alcohols
- polar
- hydrophilic
26
sulfhydryl
- part of thiols including amino acids
- polar
- hydophilic
27
carbonyl
- part of ketones and aldehydes
- polar
- hydrophilic
28
carboxyl
- part of carboxylic acids and amino acids
- negatively charged (at body pH)
- hydrophilic
29
ester
- part of dietary fats, oils, triglycerides
- aspirin is an example of an ester
30
phosphate
- part of ATP and nucleic acids
- very hydrophilic
31
Amino
- part of amino acids
- at body pH, positively charged
- hydrophilic at body pH
32
different chemical structures lead to different chemical _____
properties
33
monosaccharides / simple sugars
monomers of carbohydrates
34
carbohydrates
compounds containing carbon, hydrogen, and oxygen.
major fuel for cells
35
dehydration synthesis
a process that takes away a water molecule and links two monosaccharides or amino acids
36
hydrolisis
breaking apart a disaccharide with water
37
glycosidic bond
the bond between monosaccharides after dehydration synthesis
38
disaccharides
molecules formed by joining two monosaccharides
39
polysaccharides
molecules made of many (100s-1000s) monosaccharides
40
types of glycosidic bond
alpha and beta
41
glycogen
bond type - alpha
structure - branched /compact
function - store energy in animals
example - muscle and liver cells
42
starch
bond type - beta
structure - long straight chain
function - store energy in plants
example - corn and potato cells
43
stereochemistry
3D arrangement of atoms and molecules
44
why can humans not break down starches?
humans do not possess the enzyme to break beta glycosidic bonds in starches, instead, they act as fibres to assist in digestion
45
lipids
hydrophobic molecules made of carbon, hydrogen, and a bit of oxygen. make up 18-25% of body mass in humans
46
types of lipids
fatty acids
triglycerides
phospholipids
steroids
eicosanoids
fat-soluble vitamins
47
fatty acids
hydrocarbon chain with a carboxyl group at one end
can be saturated of unsaturated
48
saturated vs unsaturated fatty acids
saturated - contains only single covalent C-C bonds
unsaturated - contains one or more C-C double bonds
- will create a kink or bend in the chain
49
triglycerides
three fatty acids bonded to a glycerol backbone by ester bonds
50
fats vs oils
fats are triglycerides solid at room temp
oils are the same but liquid at room temp
51
adipocytes
cells that store triglycerides
52
saturated fats contain mostly _____
fatty acids
53
unsaturated fats are either ______ or _______
monounsaturated or polyunsaturated
54
monounsaturated fats examples
avocado, peanuts, olives
55
polyunsaturated fats examples
corn, sunflower, fish oils
56
phospholipids
glycerol backbone covalently linked to two fatty acids and a phosphate group
57
Polar phosphate "head" of a phospholipid is _____
hydrophilic
58
fatty acid "tails" of a phospholipid are _____
hydrophobic
59
amphipathic
molecules with hydrophobic and hydrophilic parts
60
steroids
formed by 4 fused carbon rings (cholesterol = starting molecule)
61
sterols
steroids with at least one hydroxyl group
62
what does the hydroxyl group do for sterols? why is it important?
having a hydroxyl group makes sterols amphipathic, allowing them to cross the phospholipid bilayer. It also allows them to be bound by blood proteins and transported in the blood
63
eicosanoids
- 20 carbon rings
- includes prostaglandins and leukotrienes (immune signalling molecules)
64
what is the monomer of lipids?
there is no monomer for lipids, structures are too diverse
65
proteins
mainly made of carbon, hydrogen, oxygen, and nitrogen
make up 12-18% of body mass
66
monomer of protein
amino acids
67
how many amino acids are there?
20
68
amino acids consist of: (4)
central carbon atom bonded to:
- amino group (left)
- carboxyl group (acid)(right)
- R group (top) (reactive side chain)
69
peptide bond
a covalent bond found in amino acids
70
dehydration synthesis and hydrolysis occur in:
carbohydrates (monosaccharides)
and
proteins (amino acids)
71
peptide
a few amino acids joined together
72
polypeptide
many (10-2000) amino acids joined together
73
difference between a peptide and a protein?
small proteins can be a single polypeptide chain
large proteins can be many polypeptide chains folded in complex ways
74
what determines protein function?
its structure
for reverse, what does structure determine in proteins?
75
primary structure
amino acid sequence
determined by gene sequence
stabilized by peptide bonds
76
secondary structure
repeated folds of proteins
could be alpha helicies (helix)
or
beta sheets (like folded paper)
77
tertiary structure
- 3D shape
- determined by primary and secondary structure + bonds and forces that connects the chains
- disulphide bridges between R groups stabilize
- also supported by hydrogen and ionic bonds
78
what determines 3D shape in protein folding?
hydrophobic interactions
primary/secondary structure
79
quaternary structure
- not in all proteins
- the arrangement of polypeptide chains relative to others in multi-peptide proteins
80
globular proteins
round and water soluble
81
denaturing
when proteins lose their structure and are biologically inactive
82
what denatures proteins?
pH, heat, heavy metals
83
enzymes
biological catalysts
84
cofactors
nonprotein molecules that assist enzymes
85
coenzymes
cofactors that are organic molecules
86
enzymes are: (3)
highly specific
efficient
regulated (cells control activity)
87
active site
where chemical reactions are preformed on the enzyme
88
proenzymes
inactive forms of enzymes that must be processed (usually a part must be cut off) to become active
89
nucleic acids
encode genetic material
90
nucleic acids
encode genetic material
made of carbon, hydrogen, oxygen, nitrogen, and phosphorus
can be either DNA or RNA
91
DNA is ______ to RNA
transcribed
92
RNA is _______ by ribosomes to proteins
translated
93
nucleotides
monomer of nucleic acids
can be 1 of 3 things
- nitrogenous base
- pentose sugar
- phosphate group
94
nitrogenous bases (5)
A - adenine
C - cytosine
T - thymine (in DNA)
G - guanine
U - uracil (in RNA)
95
pentose sugars (2)
deoxyribose (in DNA)
or
ribose (in RNA)
96
what are the biggest nitrogenous bases?
adenine and guanine are bigger than cytosine and thymine
97
Purines (double ring bases)
Adenine and Guanine are:
98
Pyrimidines (single ring bases)
Cytosol and Thymine are:
99
nucleic acid pairing
A pairs with T
G pairs with C
100
backbone of nucleic acid molecule consists of:
phosphate group + pentose sugar
101
why is DNA shaped like a double helix?
due to the properties of the nucleotides
phosphate makes the backbone negative
102
DNA is (general definition)
the genetic material of all living things
103
how is DNA replicated?
double helix is opened, and each strand serves as a template for a new strand to be made off of
104
semi conservative DNA replication
each daughter helix consists of one old and one new DNA strand (from the old double helix splitting)
105
RNA types
mRNA - messenger
rRNA - ribosomal
tRNA - transfer
106
mRNA
acts as the messenger between DNA and protein production
starts in nucleus, moves to ribosome
107
tRNA
transports amino acids to ribosomes during translation
108
rRNA
main component of a ribosome
provides a site for protein synthesis
109
ATP
adenosine triphosphate
energy currency in cells
110
Exergonic cellular reactions
reactions in which ATP is produced
111
endergonic cellular reactions
reactions where ATP is consumes to do cellular work
112
ATP structure
Adenine bonded to ribose bonded to a phosphate group
113
how does ATP produce energy?
the terminal phosphate is broken off by an enzyme by hydrolysis. this leaves the ATP molecule as an ADP (adenosine DIphosphate), and releases a large amount of energy
114
ADP
adenosine diphosphate
forms when the terminal phosphate is broken off of an ATP molecule
can become ATP again via synthesis with a catalyst
115
catalyst for ADP to ATP reaction
ATP synthase
