1-
Which of the following is true regarding the make-up of the ribosome?
Group of answer choices
The RNA make up more of the ribosome mass than the protein components.
It contains more RNA subunits than protein subunits.
The proteins play a larger role in the catalytic activity of the ribosome.
The nomenclature of the subunits (ie 50S) refers to the number of protein and RNA subunits
2-
Which one of the following experimental results does not support the hypothesis that the ribosome is a ribozyme?
Group of answer choices
Peptidyl transferase activity is not inactivated by treating the ribosome with detergent.
Peptidyl transferase activity can be inactivated by base changes in the rRNA.
Ribosomes from thermophilic organisms are more stable than from E. coli.
All of the answers support the hypothesis.
There are no proteins observed within 18 angstroms of the peptidyl transferase active site in the crystal structure.
3-
Which of the following best describes the tRNA binding sites of the ribosome?
Group of answer choices
All tRNAs leave the ribosome through the A site.
Each tRNA that associates with the ribosome must first bind in the P site and then moved to the A site.
Only one of the three sites can be occupied by a tRNA molecule at any given time.
The P site contains the tRNA molecule covalently bound to the growing chain of amino acids.
In: Biology
9) The site of the bacterial cell where ATP is produced is the:
a) plasma membrane
b) cell wall
c) flagella
d) nuclear region
e) cytoplasm
44) Which of the following is regulated by an operator:
a) DNA sythesis
b) protein synthesis
c) RNA synthesis
d) b and c
e) all of the above
44) Which of the following is regulated by an operator:
a) DNA sythesis
b) protein synthesis
c) RNA synthesis
d) b and c
e) all of the above
56) Single amino acids are found on:
a) DNA
b) mRNA
c) tRNA
d) rRNA
e) Proteins
77) If a solution of 1x107 bacteria/milliliter were diluted one million times and then one tenth of a milliliter of that dilution was added to a Petri dish, how many bacterial colonies would you find after incubation for one or two days:
a) 1
b) 10
c) 100
d) 1,000
e) 10,000
78) If a solution of 1x105 bacteria/milliliter were diluted ten thousand times and then one tenth of a milliliter of that dilution was added to a Petri dish, how many bacterial colonies would you find after incubation for one or two days:
a) 1
b) 10
c) 100
d) 1,000
e) 10,000
In: Biology
True or false?
True False In cell membranes, cholesterol decreases
membrane fluidity below the transition temperature, but increases
membrane fluidity above the transition temperature.
True False Escherichia coli cells grown at 40°C
would be expected to have a lower percentage of unsaturated fatty
acids in their membranes than cells grown at 20°C.
True False If a sphingolipid contains sialic acid
(a.k.a. neuraminic acid) in its oligosaccharide headgroup, the
headgroup will have a new negative charge of minus one.
True False Groups lining the pores of transport proteins
form weak non-covalent interactions with solute molecules that
replace the water molecules that normally hydrate the solute.
True False In active transport, the transported species
moves across the membrane against a concentration gradient.
True False Myristoyl, palmitoyl, and farnesyl groups
anchor otherwise soluble proteins to the extracytoplasmic face of
the plasma membrane.
True False Triacylglycerols have three ester-linked
phosphoryl groups that can in turn be ester-linked to serine,
choline, ethanolamine, or inositol.
True False In an amphipathic alpha helix, non-polar
amino acid side chains face one side of the helix, and polar
uncharged side chains face the other side.
In: Biology
Please answer all 4 questions thank you!
1) During lipid digestion, emulsification occurs in the __________________, whereas formation of chylomicrons occurs in the _____________________.
|
lumen of the small intestine; lacteals |
||
|
epithelial cells that line the wall of the small intestine; lacteals |
||
|
lumen of the small intestine; lumen of the large intestine |
||
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lumen of the small intestine; epithelial cells that line the wall of the small intestine |
||
|
lumen of the stomach; lumen of the small intestine |
2) Mass movements of fecal matter through the colon are triggered by ___________________.
|
pressure applied to the ileocecal valve as undigested matter enters the cecum. |
||
|
bacteria that reside in the colon |
||
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sympathetic innervation |
||
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the gastrocolic and duodenocolic reflexes that are triggered by digesta entering the stomach and duodenum. |
||
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the hormone, secretin |
3) Individual amino acids and glucose enter the cells that line the lumen of the digestive tract via ___________________.
|
primary active transport |
||
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sodium-linked secondary active transport |
||
|
simple diffusion |
||
|
facilitated diffusion |
||
|
endocytosis |
4) Digestion can be divided up into mechanical and chemical processes. The primary function of mechanical processes is to
|
make food particles small enough so that they can be absorbed. |
||
|
make food particles smaller so that more surface area is exposed to digestive chemicals. |
||
|
break bonds between atoms in molecules. |
||
|
activate digestive enzymes. |
||
|
separate digestible from indigestible materials. |
In: Anatomy and Physiology
5’ A C T G C C C A T G G T G C A C C T G A C T C C T G A G G A G 3’
3’ T G A C G G G T A C C A C G T G G A C T G A G G A C T C C T C 5’
5`-CUC CUC AGG AGU CAG GUG CAC CAU GGG CAG U-3`
Leu-Leu-Arg-Ser-Gln-Val-His-His-Gly-Gln
5’ A C T G C C C A T G G T G C A C C T G A C T C C T G T G G A G 3’
3’ T G A C G G G T A C C A C G T G G A C T G A G G A C A C C T C 5’
3'- GAG GTG TCC TCA GTC CAC GTG GTA CCC GTC A-5'
5'-CUC CAC AGG AGU CAG GUG CAC CAU GGG CAG U-3'
This is the translation from mRna his- arg- ser- gln- Val- his- his- gly- gln
In: Biology
In: Biology
The promoter is an important sequence for transcription of a gene. Which of these components binds to the promoter of a eukaryotic gene to allow transcription to begin? Select all that are correct.
A. Ribosomal subunits
B. A start codon
C. DNA polymerase enzyme
D. General transcription factors
E. RNA polymerase enzyme
In: Biology
Hello, does someone have a clear drawing that expresses all the biochemical pathways ( gluconeogenesis, glycolysis, ETC, citric acid cycle, glycogen synthesis, Cori cycle, the liver) how they are all integrated together?
In: Biology
1) Why is it called glycolysis?
2) What is the role of pyruvate in the glycolytic reaction?
3) How is ADP formed?
4) What role does NADH play?
5) Why is ATP important to the cell?
In: Biology
Write out the complete process of respiration, including glycolysis, the Kreb's cycle, and electron transport chain, and oxidative phosphorylation. Highlight every substrate and product for each stage, and annotate the location of each stage in the cell.
In: Biology