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Exam 2 Flashcards

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1
Q

What gives DNA its helical shape?

A

Plate stacking and Hydrogen bonding

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2
Q

In what way does a DNA strand grow?

A

5’-3’

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3
Q

In what way does the complimentary strand grow?

A

3’-5’

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4
Q

What are the steps in DNA replication for a leading strand?

A
  1. the DNA is unwinded or “unzipped” at an origin (replication fork)
  2. a short segment of RNA (primer) synthesizes and acts as a starting point for the enzyme DNA polymerase to attach to
  3. DNA polymerase then goes down the strand and replicates the strand with its matching base pair
  4. once replication is done RNA primers are then replaced with DNA by DNA polymerase
  5. any gaps left are then sealed together with enzymes
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5
Q

What are the steps in DNA replication for a lagging strand?

A
  1. the replication fork starts so that the DNA polymerase can bind and start replication
  2. a segment of RNA (primer) acts as a starting point for the DNA polymerase
  3. the DNA polymerase then has to keep unattaching and reattaching because it is moving away from replication fork instead of with the replication fork
  4. RNA primers have to continuously bind to act as starting points for replication, seeing as the polymerase keeps having to unattach and reattach, leaving it needing a new place to start
  5. once the lagging strand is replicated DNA polymerase then goes back and replaces the primers with DNA
  6. topoisomerase goes through and seals any nicks made to the strand during replication
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6
Q

What does topoisomerase’s function?

A

makes nicks in the double helix ahead of the replication fork to prevent it from getting too tightly wound up as the DNA is opened (releases tension), after replication it goes back and seals those nicks in order to avoid permanent damage

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7
Q

What keeps DNA polymerase 1 from floating away on the lagging strand whenever it has to reattach?

A

a protein known as the sliding clamp that holds DNA polymerase 3 molecules in place as DNA is synthesized, keeps the polymerase from floating away as it starts a new Okazaki fragment

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8
Q

What is an Okazaki fragment?

A

short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by enzyme DNA ligase

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9
Q

What is DNA ligase’s function?

A

to replace the RNA primers with DNA sequences

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10
Q

What is a phosphodiester bond?

A

result of a condensation reaction between a hydroxyl group of two sugar groups and a phosphate group

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11
Q

Where is a phosphodiester bond found in the DNA strands?

A

5’ end phosphate group attaching to a 3’ end sugar

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12
Q

Why is the major groove where most contact is made in DNA rather than in the minor groove?

A

the minor groove is too narrow

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13
Q

What causes the DNA backbone to be highly charged and polar?

A

the phosphate groups

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14
Q

What gives the DNA helix its stability?

A

base stacking and Hydrogen bonding

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15
Q

How many rings do purines have?

A

2 rings

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16
Q

How many rings to pyridines have?

A

1 ring

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17
Q

A G-C pair is stabilized through how many Hydrogen bonds?

A

3

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18
Q

An A-T pair is stabilized through how many Hydrogen bonds?

A

2

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19
Q

What is a sequence of nucleotides on a single strand there for?

A

to code for the RNA which then codes for the primary protein

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20
Q

Do all RNA’s code for proteins?

A

no

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21
Q

What does ribosomal RNAs code for?

A

formation of the structure of the ribosome

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22
Q

What do tRNAs do?

A

deliver amino acids to translation, they DO NOT synthesize proteins

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23
Q

What are the non used regions between genes referred to as?

A

untranslated regions (UTR)

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24
Q

Describe what untranslated regions (UTRs) do.

A

they are sites where the enzymes will assemble to transcribe the gene

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25
Q

Is eukaryotic DNA packaged into a single chromosome or multiple chromosomes?

A

multiple chromosomes

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26
Q

What are specialized DNA sequences (regions) needed for?

A

DNA replication and chromosome segregation

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27
Q

True of False, the DNA chromosome is always highly condensed.

A

True

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28
Q

What are histones?

A

group of proteins found in chromatin

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29
Q

Are histones controlled?

A

yes, they are controlled

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30
Q

Are coding regions always continuous?

A

no, they can be fragmented

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31
Q

Why won’t molecular methods let the RNA out of the nucleus until it is fully correct?

A

because of the RNA’s nonlinear coding regions

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32
Q

Why would nonlinear coding regions mess up the whole DNA sequence?

A

there would be many regions where sequenced would be present that were not needed and that would make many unneeded amino acids

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33
Q

Is the process of duplication and segregation of chromosomes highly regulated? Why?

A

yes, because lack there of can be dangerous and could lead to many unwanted problems

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34
Q

What are the discreet sites where DNA replication starts called?

A

origin of replication

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35
Q

Do interphase chromosomes randomly occupy regions or are they in their own distinct regions?

A

own distinct regions

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36
Q

What causes premature aging in children?

A

the lamith protein

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37
Q

What is found in an interphase nucleus?

A

euchromatin
heterochromatin
nucleolus

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38
Q

How is the nucleolus formed?

A

by interaction of DNA, RNAs, and Proteins

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39
Q

What was the significance of beads on a string?

A

was an argument on how the basis of DNA has something to do with this specific formation

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40
Q

What is a histone octamer?

A

DNA wrapped around a protein core of 8 histone proteins

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41
Q

How many nucleotide pairs forms the histone octamer?

A

147

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42
Q

What happens on the tails of histones?

A

they are the site of post translational modification

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43
Q

What are the three forms of post translational modification?

A

acetylation, phosphorylation, and methylation

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44
Q

What causes the DNA to be 10,000 folds shorter than the full length?

A

Chromosome packing

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45
Q

What allows access to DNA in the regulation of chromosomes structure?

A

changes in the nucleosome structure

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46
Q

Do interphase chromosomes contain both highly condensed and more extended forms of chromatin?

A

yes

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47
Q

What else, other than changes in nucleosome structure, allows access to the DNA?

A

methylation and/ or acetylation of histone proteins

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48
Q

What makes heterochromatic and euchromatic regions change in the cell?

A

outside signals to the cell

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49
Q

What do histones control?

A

which regions of the chromatin are open for expression or not

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50
Q

Define Epigenetics.

A

control of expression that is not biases on the genetic sequences, rather it is based on heredity

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51
Q

What are polymerases 2 domains?

A

one goes down the strand lining up the template, the other finds mistakes and clips (edits) them

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52
Q

How many replication forks form at each replication origin?

A

2

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53
Q

What enzyme synthesizes DNA using a parental strand as the template?

A

DNA polymerase

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54
Q

Why does RNA have to prime the DNA before the polymerase can start replication?

A

because DNA polymerase can only bind to double stranded DNA

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55
Q

What enzyme replicates the ends of eukaryotic chromosomes?

A

telomerase

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56
Q

What acts as a replication machine during DNA synthesis?

A

a group of proteins

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57
Q

What enzyme unwinds the double stranded DNA to prepare it for replication?

A

helicase

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58
Q

What enzyme primes the single DNA strand with and RNA primer?

A

primase

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59
Q

How many times does the leading strand have to be primed for replication?

A

once

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60
Q

How many times does the lagging strand have to be primed for replication?

A

continually as it is being replicated

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61
Q

Do the two replication forks move in the same direction or opposite directions on the DNA strand?

A

opposite directions

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62
Q

What are the characteristics of DNA polymerase?

A

it polymerizes (replicates) and edits the strand it is working on

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63
Q

Where is one of the most common mutations that is involved in cancer?

A

P53

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64
Q

What enzyme joins the Okazaki fragments together on the lagging strand?

A

DNA ligase

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65
Q

What does ligase use to seal the nicks to give a continuous double strand?

A

ATP

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66
Q

What are telomeres?

A

short repeating sequences at chromosome ends

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67
Q

What does telomere shrinking raise the chances of?

A

cancer

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68
Q

What happens if the DNA is A-T rich?

A

the curve of the DNA is changed, it makes it more planar

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69
Q

What would happen without a special mechanism to replicate the ends of linear chromosomes?

A

some DNA would be lost during each cell division

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70
Q

Defects in telomerase can start allowing what to happen?

A

shorter DNA in turn wiping out genes after a period of time

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71
Q

What are some reasons for continual DNA damage in cells?

A

mutations, chemically induced errors, ionizing radiation induced errors

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72
Q

What is sickle cell anemia thought to be evolved for?

A

defense in certain areas of the world where malaria is prevalent

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73
Q

What enzyme requires general transcription factors in eukaryotes?

A

RNA polymerase

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74
Q

Where are mRNAs processed?

A

nucleus

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75
Q

Are the full DNA sequences transcribed into RNA or just portions of the full sequence?

A

portions of the full sequence

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76
Q

Define introns.

A

noncoding sequences between protein-coding genes

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77
Q

How are introns removed from pre-mRNA?

A

RNA splicing

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78
Q

Where are mRNA molecules eventually degraded?

A

cytosol

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79
Q

What are the chemical differences between RNA and DNA?

A

RNA uses ribose sugar while DNA uses deoxyribose sugar
RNA uses uracil while DNA uses thymine

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80
Q

What does RNA. polymerase do for DNA?

A

transcribes it into RNA

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81
Q

Can many molecules of RNA polymerase simultaneously transcribe the same gene?

A

yes

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82
Q

What are the different types of RNAs?

A

mRNA, rRNA, miRNA, tRNA, and other noncoding RNA

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83
Q

How does RNA polymerase know when to start and stop during transcription?

A

signals in the DNA

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84
Q

Where are promoter regions located?

A

upstream of gene sequence

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85
Q

Where are terminator regions located?

A

in the transcript

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86
Q

What is RNA polymerase 1’s transcribed genes?

A

most rRNA genes

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87
Q

What is RNA polymerase 2’s transcribed genes?

A

alll protein-coding genes, miRNA genes, and other noncoding RNA

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88
Q

What is RNA polymerase 3’s transcribed genes?

A

tRNA genes, 5S rRNA genes, and genes for many other small RNAs

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89
Q

What does RNA polymerase need in order to initiate transcription?

A

general transcription factors

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90
Q

Eukaryotic promoters contain sequences that promote what?

A

binding of the general transcription factors

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91
Q

Where are mRNAs processed?

A

in the nucleus

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92
Q

Where do processed mRNAs exit?

A

nuclear pores (arrows)

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93
Q

How are eukaryotic mRNA molecules modified?

A

5’ methyl capping and polyadenylation

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94
Q

Splicing is carried out by a collection of RNA-protein complexes called?

A

snRNPs (U1, U2, U6)

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95
Q

Do some pre-mRNAs undergo alternative RNA splicing to produce different mRNAs and proteins from the same gene?

A

yes

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96
Q

How are mRNA sequences decoded?

A

sets of 3 nucleotides

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97
Q

What does tRNA do in mRNA?

A

match amino acids to codons

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98
Q

Where are mRNA messages decoded?

A

on ribosomes

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99
Q

What signals the ribosomes to stop and start on the mRNA?

A

specific codons in the mRNA

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100
Q

What factors are used as antibiotics?

A

inhibitors of prokaryotic protein synthesis

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101
Q

What do ribosomes contain?

A

RNA, ribosomal RNA, and at least 40 different proteins

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102
Q

What are the 2 different parts of the ribosome?

A

small and large subunits

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103
Q

When do proteins start folding?

A

as they are synthesized

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104
Q

what reads the codons (nucleotide triplets) in transcription from RNA to protein?

A

anticodons

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105
Q

Why is the reading frame of nucleotides important?

A

the change or mutation of act reading Fram can cause the depletion of specific proteins needed, or make unneeded proteins

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106
Q

What is a point mutation?

A

where one nucleotide is added or removed

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107
Q

What shape do all tRNAs have?

A

L-shape

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108
Q

What do tRNAs couple with in order to correct the amino acids?

A

aminoacyl synthetase

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109
Q

Where are proteins produced?

A

on polyribosomes

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110
Q

What is the first amino acid on every protein?

A

methionine (Met)

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111
Q

How do ribosomes bind to the RNA for transcription?

A

the small subunits bind first, then the large subunit binds two the small subunit

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112
Q

What happens when a ribosome and protein reach the stop codon?

A

they disassociate from each other

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113
Q

Describe cytoplasmic proteins.

A

start initiation at the 5’ end of the RNA and codes for proteins then fall apart and disassociate

114
Q

What happens to the translator?

A

it is either clipped by an enzyme or is kept as a protein

115
Q

What are the 3 ribosomal binding sites?

A

E site, P site, and A site

116
Q

What is the E, P, and A site(s)?

A

exit, polymerization, and addition

117
Q

What does a hydrolysis reaction require?

A

energy from ATP

118
Q

What are the 4 steps of the translation cycle?

A

shift, exit, open, repeat

119
Q

Where does the shift happen?

A

between the large and small subunits, this opens an entry site and eliminates the exit site

120
Q

What are the steps in tRNA processing?

A
  1. translation
  2. 5’-3’ end processing
  3. common nucleotide modifications
  4. addition of CCA to processed 3’ end
  5. nuclear export
121
Q

How is tRNA made?

A

synthesized from tRNA gene through transcription by RNA polymerase

122
Q

What are the steps in a polymerization reaction?

A
  1. denature template into single strands
  2. addition of primers to each strand for new strand synthesis
  3. extension of new DNA strand from primers
123
Q

What is required for translation initiation?

A

small ribosomal subunit, initiation factor, and loaded tRNA methionine

124
Q

What happens when a stop codon is reached?

A

it releases a factor

125
Q

Can one mRNA encode several different proteins and have multiple protein signals available to it?

A

yes

126
Q

True of false, mRNA can be degraded or translated.

A

true

127
Q

What are the 3 post translational modifications?

A

acetylation, phosphorylation, and methylation

128
Q

Many proteins require what in order to become fully functional?

A

post translational modifications

129
Q

What cell component is selectively permeable and can selectively import and export molecules?

A

plasma membrane

130
Q

What are the functions of the plasma membrane?

A

cell communication, cell growth, and cell motility

131
Q

What are internal membranes?

A

compartments for specialized metabolic functions

132
Q

What do internal membranes do?

A

import, export, and transport molecules

133
Q

What two cell components have double membranes?

A

nucleus and mitochondria

134
Q

What is the structure of a membrane?

A

lipid bilayer, embedded with proteins, and is dynamic

135
Q

Cell membranes are selective and semi permeable, what does this mean?

A

they allow some molecules to pass while restricting others

136
Q

What is the lipid bilayer?

A

flexible 2D fluid

137
Q

Where does membrane assembly begin?

A

in the endoplasmic reticulum (ER)

138
Q

What is an example of the lipid bilayer?

A

liposomes

139
Q

What does the fluidity of the lipid bilayer depend on?

A

its composition

140
Q

What is the fluid mosaic model of membranes?

A

describes cell membrane as a tapestry of types of molecules (phospholipids, cholesterols, and proteins) that are constantly moving

141
Q

Membrane growth can only happen by addition of what?

A

addition of lipids to the pre existing membrane

142
Q

certain phospholipids are confined to one side of the membrane, this results in what?

A

a resulting curvature that may assist in membrane budding

143
Q

Do membranes retain their orientation during transfer between cell compartments?

A

yes

144
Q

Are phospholipids and glycolipids symmetrically or asymmetrically distributed in the membrane bilayer?

A

asymetrically

145
Q

True or false, cholesterol is evenly distributed in the bilayer?

A

true

146
Q

A polypeptide chain usually crosses the lipid bilayer as a?

A

alpha helix

147
Q

What is the plasma membrane reinforced by?

A

the underlying cell cortex

148
Q

Can a cell restrict the movement of its membrane proteins?

A

yes

149
Q

What is the cell surface coated with?

A

carbohydrates

150
Q

What are the integral membrane proteins?

A

transmembrane proteins, monolayer associated proteins, and lipid linked proteins

151
Q

What is the peripheral membrane protein?

A

protein attached

152
Q

How can a transmembrane hydrophilic pore be formed?

A

multiple amphipathic alpha helices

153
Q

What kind of carbohydrates is the cell surface coated with?

A

glycolipids and glycoproteins

154
Q

What is an example of the reinforcement of the plasma membrane?

A

red blood cells (transmembrane, attachment, and spectrum-actin complex proteins)

155
Q

What can the cell use to restrict movement?

A

cytoskeleton, extracellular matrix, and cell-cell

156
Q

Define a tight junction.

A

junction that prevents molecules from passing through the intercellular space

157
Q

Define a desmosome.

A

anchoring junctions bind adjacent cells together like a molecular “velcro” and help form an internal ten sion reducing network of fibers

158
Q

Define a gap junction

A

communicating junctions allow ions and small molecules to pass for intercellular communication

159
Q

What is the only way the cell membrane can moves things across it?

A

diffusion

160
Q

Is the pH significantly lower of higher inside of the cell compared to the outside of the cell?

A

significantly lower

161
Q

Is the ion concentration significantly higher or lower inside of the cell compared to outside of the cell?

A

significantly higher

162
Q

How do cell signals come through?

A

ion exchange

163
Q

What gives the membrane opportunity for a current to pass through?

A

the membrane potential, one positive pole and one negative pole

164
Q

What to transporters do?

A

bind, change conformation, and move target from in to our or out to in

165
Q

Lipid bilayers are impermeable to what?

A

ions and most uncharged polar molecules

166
Q

What are the two classes of membrane transport proteins?

A

transporters and channels

167
Q

How do solutes cross membranes?

A

either passive or active transport

168
Q

What influences the passive transport of charged solutes?

A

the concentration gradient and membrane potential

169
Q

What is the process of water moving across cell membranes down its concentration gradient?

A

osmosis

170
Q

What allows an ion to pass through?

A

a pore, it travels highest to lowest concentration

171
Q

What are aquaporins?

A

where water can move through

172
Q

What doe the rate at which an ion passes through depend on?

A

size and solubility

173
Q

Sodium is mostly where in reference to the cell?

A

outside of the cell

174
Q

Potassium has a high concentration where in reference to the cell?

A

inside of the cell

175
Q

What creates a membrane potential?

A

the difference in concentrations or inorganic ions across a cell membrane

176
Q

Describe channels.

A

they open and allow flow

177
Q

Describe transporters.

A

they can be energy dependent or independent and guide molecules across the membrane

178
Q

Active transport is energy…

A

dependent

179
Q

Inactive transport is energy…

A

independent

180
Q

Do diffusion and electrostatic forces drive in the same direction or opposite directions?

A

opposite

181
Q

What happens in a sodium potassium pump?

A

potassium goes in as sodium goes out

182
Q

What are the two component forces of an electrochemical gradient?

A

the net driving force and a force from the membrane potential

183
Q

_____ move a solute along its electrochemical gradient.

A

passive transporters

184
Q

_____ actively transport a solute against its electrochemical gradient.

A

pumps

185
Q

Where are H+ gradients used mainly?

A

plants and bacteria plasma membranes

186
Q

What do electrochemical H+ gradients do?

A

drive the transport of solutes in plants, fungi, and bacteria

187
Q

What do electrochemical Na+ gradients do?

A

drive the transport of glucose across the plasma membrane of animals

188
Q

What mediates passive transport in a cell?

A

conformational changes

189
Q

What are the characteristics of passive transport?

A
  1. reversible
  2. rate of transport is concentration dependent
  3. there’s no required energy
190
Q

What is the Na+:K+ ratio in a sodium- potassium pump?

A

3 Na+ for every 2 K+

191
Q

What is the sodium-potassium pump mediated by?

A

phosphorylated aspartate

192
Q

What happens when Na+ binds to the transporter?

A

results in hydrolysis of phosphate and transporters is phosphorylated

193
Q

What happens when K+ binds to a transporter?

A

results in the dephosphorylation of the transporter

194
Q

Is there exchange present in a calcium pump?

A

no

195
Q

Define symports.

A

transfer solutes in the same direction

196
Q

Define Antiports.

A

transfer solutes in opposite directions

197
Q

Define uniports.

A

facilitate the movement of a solute down its concentration gradient

198
Q

Ion channels have what that control which inorganic ions it will allow to cross the membrane?

A

a selectivity filter

199
Q

What is a voltage gated channel?

A

passage of current alters the membrane which alters the opening and closing of a particular protein complex

200
Q

What are sterocilia?

A

oriented projections that allow for mechanical signals

201
Q

What is the trigger zone in voltage gated channels?

A

axon hillock

202
Q

What is a threshold?

A

the minimum voltage required to voltage regulated ion channels

203
Q

What is absolute refractory?

A

start of action potential when it reverts back to resting

204
Q

Can neurotransmitters be excitatory and inhibitory?

A

yes

205
Q

What happens for a period of time in a voltage gated channel?

A

after a signal the nerve cell cannot react to other signals for a period of time

206
Q

An electrical signal is converted into what at a nerve terminal in transmitter gated ion channels?

A

a secreted chemical signal

207
Q

Most phsychoactive drugs affect what by binding to neurotransmitter receptors?

A

synaptic signaling

208
Q

What does synaptic signaling enable us to do?

A

think, act, learn, and remember

209
Q

What does glycolysis produce?

A

ATP & NADH

210
Q

How does the citric acid cycle generate NADH?

A

by oxidizing acetyl groups to CO2

211
Q

Many symbiotic pathways begin with what processes?

A

glycolysis or the citric acid cycle

212
Q

Do all pathways have to enter the citric acid cycle?

A

yes

213
Q

What does the inner membrane of the mitochondria contain?

A

electron transport proteins

214
Q

Are most food molecules destined for the mitochondria for energy production?

A

yes

215
Q

What are the 3 stages of food breakdown in animals?

A

Stage 1: mouth & gut
Stage 2: cell cytoplasm (glycolysis)
Stage 3: cell mitochondria (citric acid cycle, acetyl coA)

216
Q

What is the only way fatty acids and proteins can enter the citric acid cycle?

A

through acetyl coA

217
Q

What do simple sugars form into through glycolysis?

A

pyruvates

218
Q

What are the net results of food breakdown in animals?

A

ATP
NADH
CO2
H2O

219
Q

How does glycolysis extract energy?

A

splitting sugar

220
Q

How do fermentations produce ATP with no oxygen present?

A

through the generation of NADH

221
Q

Where are organic molecules converted into acetyl coA?

A

the mitochondrial matrix

222
Q

What is pyruvate converted into?

A

acetyl coA and CO2

223
Q

What is fat stored as?

A

triglycerides

224
Q

The citric acid cycle generates NADH by oxidizing what groups to CO2?

A

acetyl groups

225
Q

Wherever CO2 is generated ____ is also generated.

A

NADH

226
Q

What are 3 high energy intermediates that contain nucleotides in their reactions?

A

acetyl coA, FADH2, and NADH

227
Q

Where does the H+ gradient exist in animal cells?

A

matrix between the two membranes

228
Q

Define catabolic.

A

breaking down molecules

229
Q

Define anabolic.

A

synthesis of molecules

230
Q

Plants store what in their chloroplasts?

A

starch and fats

231
Q

Chloroplasts carry out the metabolism of what?

A

sugar

232
Q

The mitochondria carries out what process?

A

oxidative phosphorylation

233
Q

Energy converted from food is what process?

A

oxidative phosphorylation

234
Q

energy converted from sunlight is what process?

A

photosynthesis

235
Q

NADH brings what to the membranes?

A

high energy electrons

236
Q

Chemiosmotic coupling is part of what?

A

symbiotic theory of eukaryotic evolution

237
Q

What is chemiosmotic coupling?

A

links elctron transport chain to the production of ATP through molecular machine ATP synthase

238
Q

Mitochondria divide like what through a Fischer process?

A

bacteria

239
Q

Proton pumping produces a steep electrochemical proton gradient across what in the mitochondria?

A

the inner mitochondrial membrane

240
Q

ATP has to get ___ of the mitochondria while ADP has to get ____ the mitochondria.

A

out; into

241
Q

Cytostolic mitochondria proteins require what to enter the mitochondria?

A

membrane transporters

242
Q

What does coenzyme-q (coQ) do?

A

its membrane soluble and accepts and transfers electrons within the electron transport chain

243
Q

Mitochondria moves along where in the cells?

A

microtubules

244
Q

What is associated with programmed cell death?

A

regulated changes impermeability of the mitochondrial membrane

245
Q

Coupled transport system associated with both membranes form what?

A

pores and mechanisms for the proteins to get in

246
Q

Where are electron transport chains located in the mitochondria?

A

inner mitochondrial membrane

247
Q

The prevention of cell death leads to what?

A

tumors

248
Q

Where is acetyl coA produced?

A

mitochondria

249
Q

Polysaccharides go through wha steps before it can get to acetyl coA?

A

glucose steps (glycolysis to pyruvate)

250
Q

What are the electron carriers in the citric acid cycle?

A

NADH, FADH2

251
Q

The breakdown of carbon-carbon bonds yields what compound?

A

CO2

252
Q

The movement of electrons is coupled with the…

A

pumping of protons

253
Q

ATP synthase is a reversible coupling device that can drive both…

A

ATP synthesis and hydrolysis

254
Q

What molecule absorbs light?

A

chlorophyll

255
Q

Excited chlorophyll molecules funnel energy into where?

A

reaction center

256
Q

Oxygen is generated by water splitting complex associated with what photosystem?

A

photosystem 2

257
Q

Describe carbon fixation.

A

uses ATP and NADPH to convert CO2 into sugars

258
Q

What happens in photo system 2?

A

action center, water hydrolysis, initiation of electron transport

259
Q

What happens in photosystem 1?

A

electron is delivered here, enzymatic complex system take electron to get NADPH in the dark, carbon fixation uses NADPH to make sugars in the form of starch in plants

260
Q

What are cyanobacteria?

A

microorganisms in stromatolites that carry out oxygen-producing photosynthesis changed Earth’s atmosphere

261
Q

Where does photosynthesis take place?

A

chloroplasts

262
Q

What can the thylakoid membrane system do?

A

able to capture light and turn water into oxygen

263
Q

PS2

A

contains chlorophyll, absorbs light an donates an electron

264
Q

PS1

A

carrier transports electron, generates NADPH, and uses hydrogen gradient to generate ATP

265
Q

Describe the Calvin cycle

A
  1. carbon fixation
  2. reduction
  3. regeneration of the starting molecule
266
Q

Do plants do photosynthesis AND phosphorylation

A

yes

267
Q

What is the structure of the thylakoid?

A

resembles the mitochondria but has an extra compartment

268
Q

What are the two stages of photosynthesis?

A

light dependent and light independent reactions

269
Q

What kind of light do chlorophyll molecules absorb?

A

mostly blue and red light

270
Q

What is in the middle of a Porphyrin ring?

A

magnesium

271
Q

What is light harvesting?

A

where the reaction center is surrounded by a high density of chlorophyll molecules that are all absorbing light and pass it all to the chlorophyll special pair

272
Q

What does photosystem 2 generate?

A

ATP and O2

273
Q

What does photosystem 1 generate?

A

NADPH

274
Q

What is a Plastoquinone?

A

a mobile electron carrier

275
Q

Does photosystem 1 split the water?

A

no

276
Q

Where does the special pair in photosynthesis 1 receive its electrons?

A

Photosystem 2

277
Q

What is carbon fixation catalyzed by?

A

rubsico

278
Q

ATP & NADPH from light dependent reaction is used in the cycle to form what?

A

glyceraldehyde 3-phosphate (from CO2 and H2O)

279
Q

What is the only energy lost in the carbon fixation cycle?

A

heat from all of the reactions

280
Q

Do plants store glucose?

A

no, starch

281
Q

How do chloroplasts store sugar?

A

in the form of carbohydrates and fatty acids

282
Q

Chloroplasts and mitochondria collaborate to supply cells with what?

A

metabolites and ATP

Cell Biology (4 decks)

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