EXAM 3
The ribosome is one of the largest and most complex structures in the cell. It is comprised of 1/3 protein and 2/3 RNA. The three dimensional structure shows that the catalytic site for the production of the peptide bond occurs on a protein located between the A site and the P site. True or false
False
Which of the following types of RNA are transcribed in the nucleolus? A. mRNA B. tRNA C. miRNA D. rRNA E. A and B F. C and D G. B, C and D H. All of the above I. None of the above
G. B, C and D
You have a piece of DNA that includes the following sequence: 5′-ATAGGGATTCGATCCGGATAGCAT-3′ 3′-TATCCCTAAGCTAGGCCTATCGTA-5′
'5-AUAGGGAUUCGAUCCGGAUAGCAU-3′
The P site in the ribosome is the site where the aminoacyl tRNA enters. True or False
False
The TATA binding works by binding to the nucleotides in the TATA box in the promoter of prokaryotic genes and folding the DNA in such a way that the base pairing between the nucleotides are weakened. True or False
False
The energy of sunlight is captured by the hydrophobic tail of chlorophyll molecules embedded in the thylakoid membrane. True or False
False
Plastocyanin replaces the electrons that have been taken from _____________________ reaction center.
Photosystem 1
The photosystems in chloroplasts contain hundreds of chlorophyll molecules, most of which are part of the reaction center. What is the name for the chlorophylls that donate the electrons. The special pair chlorophyll a/b the antenna complex the ferredoxin complex
the special pair
Photosynthesis is a process that takes place in chloroplasts and uses light energy to generate high-energy electrons, which are passed along an electron-transport chain. Where does the proton gradient form? thylakoid space stroma inner membrane thylakoid membrane
thylakoid space
Proteosomes degrade proteins that have been tagged with phosphate. True or False
False
A codon is _______ bases.
3
Rubisco adds a carbon dioxide molecule to 1, 3 bisphoglycerate to produce 3 phosphoglycerate. True or False
False
Rubisco can bind both oxygen and carbon dioxide, but with different affinities. True or False
False
What is the correct order of the intermediates in the Calvin Cycle?
1. RuBP 2. 3-phosphoglycerate 3. 1,3-bisphosphoglycerate 4. glyceraldehyde 3-phosphate
Match the method of phosphorylation to it's appropriate definition. All Answer Choices A. Substrate level phosphorylation B. Photophosphorylation C. Oxidative phosphorylation D. Cyclic photophosphorylation E. Repetitive phosphorylation F. Chemiosmotic phosphorylation
A metabolic reaction that results in the formation of ATP or GTP by the direct transfer of a phosphoryl (PO3) group to ADP or GDP from another phosphorylated compound. A. Substrate level phosphorylation The process of converting ADP to ATP using the energy of sunlight. B. Photophosphorylation The process of converting ADP to ATP using a chemiosmotic gradient generated by the oxidation of NADH and FADH2. C. Oxidative phosphorylation The synthesis of ATP coupled to the passage of electrons to and from Photosystem I D. Cyclic photophosphorylation
In RNA the nucleotide uracil is used instead of adenine. True or FAlse
False
Sigma factor and basal transcription factors A. both bind to the promoter region of genes. B. facilitate the binding of RNA polymerase C. facilitate the termination of transcription D. A and B E. B and C F. A and C G. All of the above H. None of the above
A. both bind to the promoter region of genes.
The start codon for translation is always ____________.
AUG or Methonine
Antibiotics, which inhibit the growth of bacteria, slow their growth by altering their ability to export proteins.
False
DNA is always found in a double helix structure, while RNA does not form secondary structures. TRue or False
False
During elongation of translation, the [A] enters the A-site. An [B] catalyzes the formation of the [C] between the adjacent amino acids. This causes the [D] to move forward on the mRNA. The [E] then moves forward as well.
Specified Answer for: A aminoacyl tRNA Specified Answer for: B RNA Specified Answer for: C peptide bond Specified Answer for: D large subunit Specified Answer for: E small subunit
Absorption of light energy by chlorophyll molecules in the absence of an electron transport chain results in The release of energy in the form of heat and light. Production of ATP An accumulation of high energy electrons. a release of energy in the form of heat and kinetic energy.
The release of energy in the form of heat and light.
Chlorophyll is located in the thylakoid membrane. the stroma. the matrix. the inner membrane.
The thylakoid membrane
What would ACG code for?
Thr
The third membrane system found in chloroplasts is called Thylacoids Stroma Cristea Matrix
Thylakoids
An alternative source for electrons for photosynthesis is hydrogen sulfate. True or False
True
Processing of mRNA occurs as soon as the RNA strand exits the polymerase. True or False
True
The ATP synthase in photosynthesis is identical to that used in aerobic respiration. True or False
True
mRNA lifespans are measured as half-lives. True or False
True
Which of the following statements about the proteasome is true? Ubiquitin is a small protein that is covalently attached to proteins to mark them for delivery to the proteasome. Proteases reside on the surface of the lower portion of a proteasome. Misfolded proteins are delivered to the proteasome, where they are sequestered from the cytoplasm and can attempt to refold. The protein stoppers that surround the central cylinder of the proteasome use the energy from peptide bond hydrolysis to move proteins into the proteasome inner chamber.
Ubiquitin is a small protein that is covalently attached to proteins to mark them for delivery to the proteasome
Hydrogen ions are pumped into the thylakoid space by cytochrome b6-f complex plastoquinone ferredoxin plastocyanin
cytochrome b6-f complex
A group of chlorophyll molecules that capture the energy in sunlight and transfer it to the photocenter is called ________________.
antenna complex
Protein expression is only regulated at the level of initiation of transcription and translation. True or False
false
Current hypothesis regarding the origin of life, suggest that energy required for the synthesis of bio-macromolecules was obtain via oxidation of organic precursors hydrogen ion gradients produce by the flow of water from white smokers lightning strikes in shallow pools heat energy from volcanic eruptions
hydrogen ion gradients produce by the flow of water from white smokers
The molecules that splice the exons in pre-mRNA are called ___________________.
snRPS
