Exam II Flashcards
(149 cards)
1
Q
what is the. cell cycle
A
the sequence of stages through which a cell passes during its lifetime
2
Q
how many cycles do the cells go through and what are they
A
6
1. Interphase
-G1
-S
-G2
2. Mitosis
- phrophase
- metaphase
- anaphase
- telaphase
3. cytoplasm divides
3
Q
what are the built-in checkpoints for?
A
stop the cycles from proceeding until certain conditions are met
4
Q
Interphase makes up____
A
most of the cycle
5
Q
What are the 3 stages
A
G1, S, G2
6
Q
G1
A
stage of cell growth and normal activity, spend most of its time here
7
Q
S
A
when DNA replication occurs (synthesis)
-makes copes of all 46 chromosomes totaling to 92
8
Q
before going to G2 what does the checkpoint do
A
stops it to make sure it replicated chromosome correctly because if not it can create mutations
9
Q
G2(2)
A
stage when cell prepares for division
-makes more membrane
10
Q
what is Mitosis
A
division of nuclear material
11
Q
what is the end result of mitosis?
A
two cells that are genetically the same as the one you started
12
Q
what is the function of mitosis
A
increase cell number during development
replace damaged dead cells later in life
13
Q
before mitosis what do cells must do?
A
duplicate each of their chromosomes
14
Q
Human cells are___
A
diploid (2 copies of each chromosome 46 total, 23 pairs) one set inherited from each parent
15
Q
what is the sex chromosome for mom and dad
A
Mom: XX
dad: XY (homologous)
16
Q
what is the end product of mitosis and cytokinesis
A
2 diploid daughter cells that are identical to the parent cell
17
Q
prophase Main events:
A
-chromosomes condense making up all the space
-Nuclear membrane breaks up to allow 2N and 2N to correct place
-mitotic spindle begins to form from microtubules
-by the end MT of spindle attach to each chromosome
18
Q
centrosomes
A
microtubule organizing centers from which Mitotic spindle extends
19
Q
how many centrosome are there and where do they move
A
2; move to opposite poles of the cell during prophase
20
Q
metaphase
A
all chromosomes are aligned midway btw the spindle poles
21
Q
Anaphase
A
Spindle microtubules separate the sister chromatids and move them toward opposite spindle poles.
22
Q
Telophase
A
23
Q
when does mitosis end
A
when a new nuclear envelope forms around each cluster of chromosomes.
24
Q
what is the difference in telophase in animal and plant cells nucleus
A
animal cells
-form nuclear membrane
Plant cell
-cell wall forms
25
cytokinesis
cytoplasmic division
26
is cytokinesis the same fro plant and animals
hell naw
27
Animal cell cytokinesis: cleavage furrow
indentation that appears in a cell's surface when the cell is preparing to divided
28
Plant cell cytokinesis: 1
1 In a dividing plant cell, vesicles cluster at the future plane of division before mitosis ends. creating a cell plate
29
Plant cell cytokinesis: 2
4 The cell plate matures as two new cell walls. These walls join with the parent cell wall, so each descendant cell becomes enclosed by its own wall.
30
does mitosis occur in prokaryotes
NOOO
31
Prokaryotic cell division: Binary fission 3
Chromosome is duplicated
Cell enlarges and splits into 2 cells
New cells are genetically identical to parent
32
Energy: living organisms___
require ongoing energy input
33
what are 2 forms of energy
kinetic enegy
-potential energy
34
Kinetic energy
light, electricity, heat motion
35
potential energy
energy stored in chemical bonds
36
one form of energy can be _____
converted to another
37
what is chemical reactions?
Processes that involve rearrangement of molecular structures to make molecules or break them down
38
what represents chemical reactions
equations
39
Energy is needed for
chemical reactions to occur
40
reactants have to be the same as
products; so that the equation is balanced
41
Equation example:
Reactants: 2H2 + 02 ---------2H20
42
activation energy
The minimum amount of energy needed to start a reaction
43
in activation energy
energy drops because it is stable
44
enzymes
Enzymes are proteins that catalyze (speed up) chemical reactions by lowering the activation energy
45
how do enzymes work
Act as catalysts, which make a reaction take place much faster
46
enzymes bind____
to a specific reactant called a substrate
47
active site
is location on the enzyme where substrate binds
48
what is metabolism
all the chemical reactions necessary to support life.
49
what are the 2 metobolic reactions
catabolism
anabolosim
50
catabolism
breaking down molecules (cellular respiration)
51
anabolism
Anabolism: making new molecules (photosynthesis)
52
what do both types metabolic reaction require?
Both types of reactions require conversion of one form of energy to another
53
Metabolic reactions are often
often multistep processes
54
Metabolic reactions can be___ or__
linear sequence or a cycle
55
what. is the sequence of metabolic reaction?
reactant - intermediate - intermediate - product
in cycle they leave a little reactant left from the product to continue cycle
56
Oxidation-reduction (redox) reactions (2)
Oxidation: when a molecule loses electrons
Reduction: when a molecule gains electrons
57
Oxidation-reduction (redox) reactions often involve
electron transfer chains
58
electron transfer chains
electrons absorb energy and transfer that energy to proteins. When protein is done charging it will bounce to other protein until completely drained of energy
59
what is the preferred cellular fuel
ATP: adenosine triphosphate
60
what to we do In ATP?
we break off one of the 3 Ps to provide energy that another molecule picks up
61
do cells breathe
nope
62
what does aerobic respiration require
02
63
what are the inputs for aerobic respiration
sugar and 02
64
what happens the sugar in A.R
it gets oxidized (break down ) - releasing energy to make ATP
65
what are the waste products for A.R
CO2 and H20
66
what is the chemical formula for A.R
C6 H12 O6 + 6O2 → 6CO2 + 6H2O
67
what are the 3 stages of A.R
Glycolysis
Acetyl-CoA formation and Krebs cycle
Electron transfer phosphorylation
68
what powers the electron transfer chain
the electrons from NADH and FADH
69
what. happens if there is no O2
Fermentation: partial oxidation of glucose that don't require O2; glycolysis happens but not other 2
70
what are photosynthesis reactant
CO2 and H20
71
what are photosynthesis products
sugar and 02`
72
What are autotrophs
like plants they can make their own food
73
how can autotrophs make their own food?
harvest energy from the sun and carbon from the atmosphere (CO2)
74
what are heterotrophs
get carbon, food from organic molecules made my autotrophs
75
what does photosynthesis require
pigment
76
what is pigment
organic molecule that absorbs a specific wavelength of light
77
what is the most common pigment
Chlorophyll A: absorbs red/violet light and reflects green (what we see)
78
How pigments work: 1
absorbs light a particular wavelength
79
How pigment work: 2
electrons in pigment absorb light energy and get energized
80
How pigment work: 3
light energy captured by electrons in pigment is used to make glucose
81
where can photosynthesis occur?
in chlorolplasts of eukaryotic organisms
82
what are the two stages of of photosynthesis
1. light dependent reaction
2. light independent (dark) reactions
83
Where does light dependent reactions occur
in thylakoid membrane (inner membrane dark green part)
84
Light dependents reactions main events (3)
1. light energy is absorbed bu pigments and converted to ATP and NADPH
2. water molecules are split releasing 02 as a waste
85
what are the light dependent reactions input
sun
h20
86
what are the outputs of light dependent reactions
-02
-NADPH and ATP
87
Where does light independent reactions occur
in the stroma (liquid portion)
88
Light independent reactions main events
- series of reactions that make sugar
-carbon is extracted from atmosphere CO2 (carbon fixation)
89
what does light independent use as a fuel
NADPH and ATP from light ReCTIONS
90
HOW does co2 get into cells
plant have small opening called stomata on leaves
91
what is the function of stomata
allow co2 to enter and o2 to leave plant
-close temporarily on hot days to prevent too much water loss`
92
how many PGL molecules are produced at the end of dark reactions
12
93
how many of those are needed to make glucose
2
94
What is the glucose that is made during photosynthesis used for in the plant
1: sent to cytoplasm to mitochondria make more ATP
2. store as starch to Make atp
3. to make cell wall
95
True or false is DNA a polymer
TRUE
96
what are the monomers of DNA
Nucleotides
97
what are three parts of the nucleotides
1. phosphate
2. dexyribose
3. nitrogen containing bases
ATCG
98
what does it mean when it says strands are antiparallel
69
99
DNA in eukaryotes is organized as
chromomes
100
Histones?
spools Dan wrapped around to fit more
101
what are genes?
chromosomes containing specific pieces of DNA
102
what do genes contain?
instructions for making proteins
103
DNA is wrapped around what to fit into the nucleus
histones
104
what are the is of converting DNA into finished duplicated chromosomes
1. the two strands of DNA twist into a double helix
2. dna wraps around histone protein
3. dna/proteins twist tightly Into a fiber
4. fiber coils over again to form a hollow cylinder
5. when duplicated it has an X shape
105
how many chromosomes does a prokaryote have?
one
106
how many chromosomes are in eukaryotes?
there is 46 chromosomes= 23 pairs
107
what are chromosomes 1-22
autosomes
108
what is chromosome 23
sex chromo; (XX XY)
109
how are human chromosomes arranged
by length (largest to smallest)
110
which is shortest/longest: X Y
x Is longest
y shortest
111
what phase are the chromosomes copied entirely
s phase
112
how are chromosomes copied?
several enzymes that unwind the chromosomes and make new DNA using old strands as templates; SEMI conservative
113
what is semi conservative?
each new molecule contains one old and one new strands
114
what are the four enzymes needed to replicate DNA?
Topoisomerase
Helicase
DNA Polymerase
DNA ligase
115
TOPOisomerase
untwist double helix
116
Helicase
separates 2 strands
117
DNA polymerase
reads templates and also makes new DNA
118
DNA Ligase
joins new fragments of DNA together
119
Mutation?
any change in DNA sequence
120
can be caused by:3
- errors during replication
-UV lights or Xrays
-certain chemicals (mutagens) found in tobacco
121
how do we get from a DNA sequence to a protein that does a job for a cell?
-Genes
-Transcription
-Translation
122
genes contain_____
the protein making informarion
123
Transcription? + where is happens
make copy of DNA instructions in mRNA and then it leave the nucleus
124
Translation + where it happens
mRNA goes into cytoplasm to ribosomes and translates in the language of proteins which is amino acids
125
Difference in function of RNA and DNA
DNA stores cells genetic info RNA serves as disposable copies of DNA genetic message
126
3 types of RNA
-mRNA
-rRNA
-tRNA
127
mRNA: Messanger RNA
contains protein code transcribed from genes
128
rRNA: ribosomal rna
makes proteins
129
tRNA: transfer rna
brings amino acids to ribosomes so they can make proteins
130
which is the major enzyme involved in transcription
RNA polymerase
131
how many strands are used as a template during transcription
1
132
what does a rna polymerase bind to
a promoter near start of gene sequence
133
what is the function of rna polymerase
-reading DNA template strand
-unwinding/separating DNA strands as it moves
-links together rna nucletocies as it reader DNA template
134
after transcription the mRNA must be
modified
135
what are exons and introns
ex: contain protein instructions
intro-dont
136
how is the mRNA modified: 3
-introns removed
-5' cap added
-3' AAAAAAAAA tail added
(cap and tails help ribosome know where to start translation)
137
who is the major player in translation? why
ribosome: translate code and links together amino acids
138
what is the ribosome made of?
proteins and rRNA
139
where is the protein building information stored
in codons
140
codons are sequences of _____
3 mRNA nucleotides
141
each codon is code for a specific?
amino acid
142
how is the order of the amino acids dictated in a protein?
order of codons in the mRNA sequence
143
how many amino acids?
20
144
every protein starts with why
methionine (M) (MET) indicates ribosome where ro start
145
how many total codons are there
64
146
how many codons are for amino acids
61
147
what at are the 3 codons left for
stop codons (UUA, UGA, ) to indicate when to stop
148
what is the initiator codon
AUG (methoinie)
149
what happens after amino acid chain is complete
fold into 3d shape
folded/processed in rough er
sent to Golgi body for sorting packing and shipping to destination in cell
