Upgrade to remove ads
BIOSCI 93 MIDTERM 2 REVIEW
Terms in this set (114)
What is the equation for photosynthesis?
6 CO2 + 12 H2O + light energy --> C6H12O2 + 6 O2 + 6 H2O
Where does the Calvin cycle occur?
The Calvin cycle occurs in the stroma.
The light reactions of photosynthesis use __________ and produce ___________.
water ... NADPH
What process produces oxygen?
Which set of reactions uses H2O and produces O2?
The light-dependent reactions
What is the importance of the light-independent reactions in terms of carbon flow in the biosphere?
The light-independent reactions turn CO2, a gas, into a usable carbon in the form of sugars.
What does the light-dependent reactions of photosynthesis use and produce?
uses water and produces oxygen
What is the primary product of photosystem I?
What is NADPH, produced by photosystem I, used for?
To supply energy for the production of sugars during photosynthesis
What is the biological significance of light-independent reactions of photosynthesis?
They convert carbon dioxide to sugar.
All organisms use the sugars produced by photosynthesis to generate energy.
What is the relationship between light-dependent and light-independent reactions of photosynthesis?
The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.
What reaction ensures that the Calvin cycle can make a continuous supply of glucose?
Regeneration of RuBP
What is the function of RuBP?
It fixes carbon dioxide into an organic molecule that is used to produce sugar.
What describes ATP production resulting from the capture light energy by chlorophyll? Why?
The excitation of chlorophyll by light energy initiates a chain of events that leads to ATP production
What is does the chemiosmotic hypothesis state?
It states that the flow of electrons through an electron transport chain generates a proton gradient that leads to the synthesis of ATP.
According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?
Proton gradient -- by the enzyme ATP synthase
Inputs of the light reactions?
Outputs of the light reactions?
Inputs of the Calvin cycle?
Outputs of the Calvin cycle?
In the light reactions, light energy is used to oxidize __________ to _______.
H2O to O2
The electrons derived from this oxidation reaction in the light reactions are used to reduce ____________ to ____________.
NADP+ to NADPH
The Calvin cycle oxidizes the light-reactions product ____________ to ___________.
NADPH to NADP+
The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce __________ to ___________.
CO2 to G3P
What are the functions of Photosystem II?
oxidation of water
reduction of electron transport chain between two photosystems
What are the functions of Photosystem I?
reduction of NADP+
oxidation of electron transport chain between two photosystems
What are the functions of both PS II and PS I?
reduction of primary electron acceptor
Where do the electrons that enter the electron transport chain come from in photosynthesis? In cellular respiration?
photosynthesis: water molecules
cellular respiration: NADH and FADH
What products formed from the light reactions enter the Calvin cycle?
ATP and NADPH
During ____________ the cell grows and replicates both its organelles and its chromosomes.
DNA replication produces two identical DNA molecules called _______________, which separate during mitosis
After chromosomes condense, the __________________ is the region where the identical DNA molecules are most tightly attached to each other.
During mitosis, microtubules attach to chromosomes at the _________________.
In dividing cells, most of the cell's growth occurs during _____________.
The __________________ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division.
During interphase, most of the nucleus is filled with a complex of DNA and protein in a dispersed form called ______________.
In most eukaryotes, division of the nucleus is followed by ______________, when the rest of the cell divides.
The ________________ are the organizing centers for microtubules involved in separating chromosomes during mitosis.
Once a cell passes the G1 checkpoint, it ___________.
divides (completes the cell cycle)
The first step in preparing for division is to replicate the cell's DNA in the _____________.
In the G2 phase, the ______________ replicates.
In the early M phase, the centrosomes ________________ from each other toward the poles of the cell, in the process of forming the ______________.
move away; mitotic spindle
At the end of the M phase, the cell ___________, forming two ___________________________.
divides (cytokinesis); genetically identical daughter cells
During prophase, the microtubules of the mitotic spindle ___________.
During anaphase, the nonkinetochore microtubules ___________ and move past each other, and the kinetochore microtubules ____________.
During telophase, the nonkinetochore microtubules _______________.
After chromosomes duplicate, are the two sister chromatids that form identical? What is the significance of centromeres?
Yes; centromeres are the region of the chromosomal DNA where the chromatid is attached most closely to its sister chromatid
Mitotic phase (M)
includes mitosis and cytokinesis
the period of the cell cycle is not dividing; cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase
synthesis part of cell cycle - DNA is replicated
first gap, or growth phase of the cell cycle
- nuclear envelope encloses the nucleus
- nucleus contains one or more nucleoli
- two centrosomes have formed
- chromosomes cannot be seen individually
- chromatin fibers condense into chromosomes
- nucleoli disappear
- sister chromatids are visible
- mitotic spindle begins to form
- nuclear envelope fragments
- microtubules extend and invade nuclear area
- chromosomes have become more condensed
- chromatids have kinetochore, a specialized protein structure at centrosome
- microtubules attach to kinetochore
- centrosomes are at opposite sides
- chromosomes at the metaphase plate - centrosomes lie there
- sister chromatids part
- kinetochore tubules shorten, chromosomes move to opposite sides
- cell elongates
Telophase & Cytokinesis
- two daughter nuclei form - nucleoli disappear
- chromosomes less condensed
a protein released by certain cells that stimulates others to divide
a phenomenon in which crowded cells stop dividing
the requirement that a cell must be attached to a substratum in order to initiate cell division
a mass of abnormal cells with specific genetic and cellular changes such that cells are not capable of surviving at a new site and generally remain at the site of origin
cells whose genetic and cellular changes enable them to spread to new tissues and impair the functions of one or more organs
spread of cancer cells to locations distant from their origin
____________ joins DNA segments into a continuous strand.
What happens after DNA replication is completed?
each new DNA double helix consists of one old DNA strand and one new DNA strand
The action of helices creates ________________ and __________________.
replication forks and replication bubbles
What catalyzes DNA synthesis?
What happens when a primer is added to a single strand of DNA?
DNA polymerase can start adding nucleotides to synthesis a complementary strand
What enzyme creates a primer for DNA polymerase?
What is the function of the enzyme Topoisomerase?
This enzymes untwists the coils that occur in the DNA as it is being unwound into single-stranded template.
What is transcription?
The process by which a DNA template is used for the manufacture of several different types of RNA
What is translation?
The process by which information encoded in RNA is used to manufacture a polypeptide
What is the process in which pre-mRNA is edited to mRNA?
What happens in RNA processing?
edits the RNA transcript that has been assembled along a DNA template
What is a promoter?
the site where the RNA polymerase must bind to initiate transcription
The promoter is a __________________ region of a gene.
What determines which base is to be added to an RNA strand during transcription?
the base pairing between the DNA template strand and the RNA nucleotides
Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand?
complementary, because the template strand determines the nucleotides to be added to the RNA strand
What happens to RNA polymerase II after it has completed transcription of a gene?
It is free to bind to another promoter and begin transcription.
The direction of synthesis of an RNA transcript is ___________________.
5' to 3' -- nucleotides are added to the 3' end of RNA
What does RNA polymerase do?
Untwists a portion of the DNA double helix
The ______________ is the region of DNA at which the process of transcription begins.
What are the events in the transcription of a gene?
1) RNA polymerase binds promoter
2) RNA polymerase transcribes gene
3) RNA polymerase reaches terminator
4) RNA polymerase exits gene, RNA is released
RNA polymerase reads the sequence of DNA bases from the _________________ strand.
RNA polymerase reads the code from the template strand in the ______________________ direction and thus, produces the mRNA strand in the ______________________ direction.
3' to 5'
5' to 3'
In RNA, uracil replaces ____________.
What ultimately determines which DNA strand serves as the template strand?
the base sequence of the gene's promoter
Where does translation take place?
Which nucleic acid is translated to make a protein?
mRNA - it is the message that is translated to make a protein
___________________ is an example of a post-transitional modification.
What is meant by translocation?
The ribosome slides one codon down the mRNA.
A _____________ is a group of three bases that can specify only one amino acid.
What is the start codon?
What are the stop codons?
UAA, UAG, UGA
What are the three steps in adding a new amino acid?
1) Binding of the charged tRNA to the A site
2) Formation of the new peptide bond
3) Movement of the mRNA through the ribosome
What are the two categories of point mutations?
a nucleotide-pair substitution
a nucleotide-pair insertion or deletion
Nucleotide-pair substitutions can result in what kinds of mutations?
silent, missense, nonsense
What is a silent mutation?
does not change the amino acid sequence of a polypeptide
What is a missense mutation?
causes one amino acid to be substituted for another, which can have a range of effects
What is a nonsense mutation?
results in the production of a premature "stop" signal; translation will terminate early --> nonfunctional proteins
What is glycolysis?
"sugar splitting" - breaks glucose into pyruvate; the first step of cellular respiration that occurs in the cytosol
What is pyruvate oxidation?
oxidizes pyruvate to acetyl CoA to carbon dioxide; this second step of cellular respiration occurs in the mitochondrial matrix of eukaryotic cells and cytosol of prokaryotes
What is the citric acid cycle?
oxidizes acetyl CoA to carbon dioxide; second step of cellular respiration occurs within the mitochondrial matrix in eukaryotic cells and cytosol of prokaryotes
What is oxidative phosphorylation?
it is the production of ATP using energy derived from redox reactions of an electron transport chain; final step of cellular respiration that occurs in the inner mitochondrial membrane
Reactants of glycolysis?
glucose, NAD+, ADP, Pi
Products of glycolysis?
Pyruvate, ATP, NADPH
Reactants of Pyruvate?
Products of Pyruvate?
Acetyl CoA, CO2, NADH
Reactants of Citric acid cycle?
Acetyl CoA, NAD+, FAD
Products of citric acid cycle?
CO2, ATP, NADH, FADH2
Reactants of Oxidative phosphorylation?
NADH, FADH, ADP, Pi
Products of Oxidative phosphorylation?
ATP, H2O, NAD+, FAD
What are northern blots used to read?
RNA at transcription level
What are western blots used to read?
antibodies to visualize proteins
This set is often in folders with...
BIO 93 Midterm2
UCI Bio 93 Midterm 2
You might also like...
Bio 101 exam 3 Hinton
Chapter 10 & 12 Mastering Biology Questions
Review for Biology Exam 2
AP Biology Ch. 5
Other sets by this creator
Medical Term of the Day
PH 1 Final Review - Chapter Reviews
Public Health 1 End of Chapter Review Q's
Public Health 1 Chapter Reviews