Exam 1 Flashcards
1
Q
define evolution
A
a change in the genetic structure of a population individuals don’t evolve
2
Q
natural selection
A
differential reproduction
3
Q
what two things does natural selection need?
A
population needs genetic variation and variation must be heritable
4
Q
the oxygen and hydrogen in water is combined by what kind of bonds?
A
polar covalent bonds
5
Q
define hydrophobic and give example
A
non-polar molecules that repel water, example hydrocarbons
6
Q
define hydrolysis
A
break down protein using water
7
Q
define anabolic reactions
A
build polymers, need energy, loses water
8
Q
define catabolic reactions
A
break down polymers, release energy, need water to break apart the covalent bonds
9
Q
2 different water molecules are combined by which type of bond
A
hydrogen bonds
10
Q
what are the 4 types of carbon atoms?
A
nucleic acids, lipids, carbohydrates, and proteins
11
Q
define electronegative
A
molecules that pull electrons close to it when bonding with hydrogen ex: oxygen
12
Q
why can insects walk on water?
A
due to water’s high surface tension due to cohesion
13
Q
define specific heat
A
it takes a large amount of energy to raise the temp of water
14
Q
why is it important that water has a high specific heat
A
it helps aquatic life because the water temp of their environment remains stable when the outside is changing
15
Q
why is the freezing of water significant?
A
the hydrogen bonds keep the molecules spacious from one another to form a 3-dimensional crystal formation allowing it to be less dense than liquid water and allowing it to float
16
Q
define amphipathic
A
molecule is both hydrophobic and hydrophilic ex: phospholipids macromolecules
17
Q
what 3 classes of macromolecules are formed together through the synthesis of many monomers?
A
carbohydrates, nucleic acids and proteins
18
Q
what is carbohydrates monomer?
A
monosaccharides
19
Q
what are 3 functions of carbohydrates?
A
fuel source (store energy), cell-cell recognition in immune response, role in structural support and lay role in formation of nucleic acids
20
Q
what are nucleic acids?
A
make up RNA and DNA
21
Q
5 examples of monosaccharides
A
fructose, glucose, ribose, galactose, and ribulose
22
Q
what is a disaccharide?
A
sugar formed by a condensation reaction between two monomers
23
Q
what is maltose
A
glucose + glucose
24
Q
what is sucrose
A
glucose + fructose = table sugar
25
what is lactose
glucose + galactose = milk sugar
26
4 examples of polysaccharides
starch, glycogen, cellulose and chitin
27
when is starch used?
used by plants to store surplus sugar (potato)
28
when is glycogen used?
how animals store surplus sugar in their lives
29
what is cellulose?
most abundant polymer on the planet, important in plant cells, humans cannot digest but has FIBER
30
what is chitin?
some animals and fungi are made up of chitin ex: crabs
31
what is the monomer of proteins?
amino acids
32
what is the polymer of proteins?
polypeptides
33
how many different amino acid groups are there?
20
34
what is different about each amino acid?
the R group
35
what are the 3 different types of R-groups?
nonpolar, polar, and electrically charge
36
what is proteins structure?
amino group (H-N-H), carboxyl group(O=C-OH), variable group (R) and hydrogen
37
define primary structure
the sequence of amino acids in a protein
38
define secondary structure
the regions of the molecule that are coiled/folded, have H-bonding between different R-groups
39
define tertiary structure
hydrophobic & hydrophilic reactions, overall shape of the protein due to interaction between the side chain (R groups) of the amino acids
40
define quaternary structure
proteins that are made of more than one polypeptide chain
41
define sickle-cell anemia
genetic disease that results in an abnormal production of the protein hemoglobin (quaternary), abnormality in the 6th position of the B subunit, has a VALINE in the 6th position instead of a GLUTAMIC ACID
42
what does valine do?
causes hemoglobin molecules to rearrange into rods which makes it impossible to carry oxygen
43
what is alanine?
nonpolar (hydrophobic) R group
44
what is threanine?
polar (hydrophilic) R group
45
2 traits of lipids
all hydroPHOBIC and they are NOT POLYMERS
46
2 main functions of lipids
energy storage and they are the main structural components of cell membrane and hormones
47
what are 3 types of lipids
dietary fats (triacylglyceroids), phospholipids (cell membrane) and steroids (cholesterol, estrogen and testosterone)
48
what are triacylglyceroids?
dietary fats that are formed when 3 fatty acids and 1 glycerol molecule is joined via condensation synthesis ex: fats and oils
49
what are two types of triaclglyceroids?
saturated and unsatured
50
what is a saturated fat?
only have SINGLE bonds, STRAIGHT chains and SOLID
51
what is an unsaturated fat?
have double bonds, kinks in structure and LIQUID
52
what is hydrogenation?
process where liquid unsaturated fat is converted to a solid saturated fat
53
what are 3 things fats are used for?
protection, insulation and energy source
54
what are phospholipids?
amphipathic molecules that have only 2 fatty acid molecules and a glycerol jointed to a phosphate group, 2 hydrophobic tails and 1 hydrophilic head AND forms the basis of the phospholipid bilayer of cell membranes
55
what are steroids?
a four-fuced ring structure. including cholesterol and hormones
56
4 functions of cholesterol
precursor molecule for steroidal hormones (estrogen), molecule found in cell membranes, enables body to make vitamin D and used to make bile acids for digestion
57
what are the two types of cholesterol?
HDL and LDL
58
what is HDL?
"good cholesterol", less cholesterol and more proteins
59
what is LDL?
"bad cholesterol", more cholesterol and less proteins
60
what is the monomer of nucleic acids?
nucleotides
61
what is a nitrogenous base?
a ringed structure consisting of nitrogen, carbon and hydrogen
62
what is RNAs sugar?
ribose
63
what is DNAs sugar?
deoxyribose
64
what is RNA made up of?
adenine, guanine, cytosine and URACIL
65
what is DNA made up of?
adenine, guanine, cytosine and thymine
66
what is the different between DNA and RNA?
DNA is paired and RNA is single stranded
67
how old is the universe?
13.7 billion years old
68
how old is the solar system?
4.55-4.56 billion years old
69
how old is the earth?
4.5 billion years old
70
when did we first see life?
3.5 billion years ago
71
what does earth's surface being dynamic mean?
the environment of earth is always changing
72
define abiotic
no life when earth was first formed, about 3.5-4 billion years ago
73
what are cons about the evidence of life?
they cannot recognize bacteria, cannot determine size of pop, hard bodies are easier to find than soft bodies, hard to find if they didn't live near water
74
how do we look at organisms with poor or no fossil record?
common ancestors/DNA
75
define relative dating
type of dating fossils, deeper sedimentary levels formed earlier and their fossils are older than those found in shallow layers of rock ex: bottom layer has more than the top
76
define absolute dating
better then relative, specifically tells a date
77
what are the two types of absolute dating?
radiometric dating and dendrochronology
78
what is carbon-14 half life and what is its daughter atom
5730 years then it turns into nitrogen-14
79
what is carbon-14 best for dating
<50,000 years
80
what are assumptions of carbon-14 dating?
that the amount of CO2 in the atmosphere is constant. they ignore industrial resolutions and nuclear weapon testing
81
what is dendrochronology?
sees how the environment effect tree growth, most precise because it dates back to the exact year and season
82
what is dendrochronology best used for?
about <9,000 years
83
what is the Smokey Bear effect
suppression of forest fires that has led to dense forests of trees and undergrowth in the southwestern US
84
what are the conditions of early earth?
there was not a lot of free oxygen and its important bc if there was a lot, life couldn't have arisen from inorganic compounds ((O is oxidizing and the atmosphere was reducing))
85
what is the Miller-Urey experiment?
he mixed together gases that were available in early life and found organic compounds. proved that organic compounds could have grew in abiotic conditions
86
define heterotrophs
consume organic molecules
87
define autotrophs
inorganic sulfur and iron compounds to gain energy
88
define plate tectonics
movement of earths plate due to activity at spreading centers and subduction zones
89
define continental drift
the fact that continents are constantly rearranging
90
define Pangea
when all the landmasses were joined 250 millions years ago, explains similarities observed in modern organism an separate landmasses
91
define the geological time scale
classification of different period in Earth's history
92
what are the 4 eras
Precombrian, Paleozoic, Mesozoic, and Cenzoic
93
what is sedimentary rock?
the best source of fossil, formed by layers of minerals that settle out of water
94
what are the 3 major domains?
bacteria, archaea and eukarya
95
what are the 3 shapes of prokaryotes?
coccus (spherical), bacillus (rod) and spirillum (helical)
96
what is LUCA
the last universal common ancestor, arose over 3.5 million years ago, believed it was a sophisticated organism with complex structure
97
describe Archaea
prokaryotes, extremophiles
98
what are 3 reasons why prokaryotes grow and divide quickly
1. small genome, 2. simple morphologies 3. reproduce via binary fission
99
define binary fission
cell division in which a prokaryote chromosome replicates and the mother cell pinches in half to form two daughter cells that are identical. form of ASEXUAL reproduction
100
define nucleoid
where DNA is concentrated in prokaryotes
101
define plasmids
smaller rings of extrachromosomal DNA, may contain genes that provide resistance to antibiotics
102
what are 3 types of gene transfer?
transformation, conjugation and transduction
103
define transformation
prokaryotes acquire genes from environment
104
define conjugation
when 2 living prokaryotic cells physically join with one another. only one way
105
what is the F factor
the fertility factor plasmid (F+), they are hereditary and contagious
106
what is transduction
the exchange of DNA between prokaryotes by phages
107
2 ways of transduction
Lysogenic Cycle and Lytic Cycle
108
what is the Lysogenic Cycle
phage integrates directly into the bacteria's DNA
109
what is the Lytic Cycle
phase attaches to cell then produces copies of the phage then the cell bursts and new phages go free
110
what are 5 main functions of protein?
digestion, color pigment, muscle movement, attack bacteria and viruses, and transport oxygen to all cells of the body
111
how are two strands of DNA double helix held together?
hydrogen bonds between nitrogenous bases
112
south-facing side of the evolutionary canyons
African slopes, yellowish/brownish, extreme variable conditions
113
north-facing side of the evolutionary canyons
European slopes, dark brown/black, temperament evolutionary conditions
114
based on what we've learned, the first life forms were most likely what?
obligate anaerobes
115
what are 2 things that make up domain bacteria
peptidoglycin in their cell walls and some are photosynthetic
116
what are 3 things that make up domain archaea
they have unique cell membrane lipids, have introns in some genes and are mostly anaerobic
117
define nitrogen fixers
plant gets nitrogen from bacteria and bacteria gets carbon from plant
118
what does Vibrio cholerae cause?
diarrhea
119
what does Yersina pertsis cause?
the plague
120
define saprobe
organism that lives off decaying matter
