Advanced Cell Biology Exam 1
Questions with Actual Verified
Solutions.
What are the three big picture ideas of cell biology? - Answer 1. All living organisms descend
from a common ancestral cell (~3.9-2.5 billion years ago)
2. The genetic material provides the "blue print" for a cell and an organism
3. Changes in the genetic material (mutations) drive evolution
What results from the fact that all living organisms descend from a common ancestral cell? -
Answer we see a high degree of conservation in the genetic make up, protein sequence and
function and cell architecture throughout life which justifies the use of "model organisms" in
research.
Why are model organisms used? - Answer they are easy to use in the lab and have been
historically used, so tools have been developed to study them, which saves time
What are some examples of model organisms? - Answer bacteria, yeast, fruit fly, and mice
What are the building blocks of proteins? - Answer amino acids
How is DNA converted into the amino acid sequences of proteins? - Answer 1. transcription
factors bind to the regulatory region of a specific gene and activate it
2. multiprotein initiation complex forms and binds to the DNA
3. RNA polymerase begins transcription of an activated gene at the start site by moving along
the DNA linking nucleotides into a single-stranded pre-mRNA transcript using the DNA strand as
a template
4. The transcript is processed to remove noncoding sequence
5. The mature mRNA moves to the cytoplasm, where it is bound by ribosomes that read its
sequence and assemble a protein by chemically linking a.a. into a linear chain
principle players in cell biology categorized into what two groups - Answer small molecules
(sodium, water, glucose, serine, oleic acid)
macromolecules (polysaccharides, proteins, nucleic acids)
, What are some functions carried out by proteins? - Answer structure, transport, movement,
regulation, enzyme catalyst, signaling
Describe protein structure. - Answer 1. Primary: sequence of amino acids (amino (N)
terminus=5' and the carboxyl (C) terminus=3')
2. Secondary: internal local folds (alpha helixes and beta sheets)
3.Tertiary: complex three-dimensional shape
4. Quaternary: protein associates with other proteins to form multiunit structure
Native State - Answer A protein's most stable conformation (a.a.'s provide information
needed for folding)
chaperones - Answer proteins that assist in the folding of proteins (Hsp70 and Hsp90)
Describe Hsp70 proteins. - Answer Heat shock proteins
Identified based on the fact that their cell expression level increases with high temperatures
(activated by heat shock)
This makes sense because at high temps, some proteins may be denatured and need to be
refolded
[number 70= 70 kd= weight of the protein]
Describe Hsp70 mediated protein folding. - Answer 1. Hsp70 operates both on protein just
being born or a fully completed protein (transiently binds to the nascent polypeptide as it
emerges from a ribosome, or an unfolded protein)
2. Unfolded protein substrate rapidly binds the open conformation substrate-binding domain of
the Hsp70 protein (ATP is bound to the nucleotide-binding domain of the Hsp70
3. Hsp70 naturally hydrolyzes ATP to ADP (co-chaperone accessory proteins, DnaJ and Hsp40,
help facilitate this action and increase the rate of formation of ADP)
4. Hydrolysis results in a conformational change of the substrate-binding domain (closed form)
5. This shape clamps onto protein and locks it into the SBD allowing for protein folding
[molecular chaperones inhibit "bad" folding patterns]
6. ADP now "falls" off and new ATP binds (GrpE and BAG1 facilitate this exchange), converting
Hsp70 back into its open form and releasing the protein
Questions with Actual Verified
Solutions.
What are the three big picture ideas of cell biology? - Answer 1. All living organisms descend
from a common ancestral cell (~3.9-2.5 billion years ago)
2. The genetic material provides the "blue print" for a cell and an organism
3. Changes in the genetic material (mutations) drive evolution
What results from the fact that all living organisms descend from a common ancestral cell? -
Answer we see a high degree of conservation in the genetic make up, protein sequence and
function and cell architecture throughout life which justifies the use of "model organisms" in
research.
Why are model organisms used? - Answer they are easy to use in the lab and have been
historically used, so tools have been developed to study them, which saves time
What are some examples of model organisms? - Answer bacteria, yeast, fruit fly, and mice
What are the building blocks of proteins? - Answer amino acids
How is DNA converted into the amino acid sequences of proteins? - Answer 1. transcription
factors bind to the regulatory region of a specific gene and activate it
2. multiprotein initiation complex forms and binds to the DNA
3. RNA polymerase begins transcription of an activated gene at the start site by moving along
the DNA linking nucleotides into a single-stranded pre-mRNA transcript using the DNA strand as
a template
4. The transcript is processed to remove noncoding sequence
5. The mature mRNA moves to the cytoplasm, where it is bound by ribosomes that read its
sequence and assemble a protein by chemically linking a.a. into a linear chain
principle players in cell biology categorized into what two groups - Answer small molecules
(sodium, water, glucose, serine, oleic acid)
macromolecules (polysaccharides, proteins, nucleic acids)
, What are some functions carried out by proteins? - Answer structure, transport, movement,
regulation, enzyme catalyst, signaling
Describe protein structure. - Answer 1. Primary: sequence of amino acids (amino (N)
terminus=5' and the carboxyl (C) terminus=3')
2. Secondary: internal local folds (alpha helixes and beta sheets)
3.Tertiary: complex three-dimensional shape
4. Quaternary: protein associates with other proteins to form multiunit structure
Native State - Answer A protein's most stable conformation (a.a.'s provide information
needed for folding)
chaperones - Answer proteins that assist in the folding of proteins (Hsp70 and Hsp90)
Describe Hsp70 proteins. - Answer Heat shock proteins
Identified based on the fact that their cell expression level increases with high temperatures
(activated by heat shock)
This makes sense because at high temps, some proteins may be denatured and need to be
refolded
[number 70= 70 kd= weight of the protein]
Describe Hsp70 mediated protein folding. - Answer 1. Hsp70 operates both on protein just
being born or a fully completed protein (transiently binds to the nascent polypeptide as it
emerges from a ribosome, or an unfolded protein)
2. Unfolded protein substrate rapidly binds the open conformation substrate-binding domain of
the Hsp70 protein (ATP is bound to the nucleotide-binding domain of the Hsp70
3. Hsp70 naturally hydrolyzes ATP to ADP (co-chaperone accessory proteins, DnaJ and Hsp40,
help facilitate this action and increase the rate of formation of ADP)
4. Hydrolysis results in a conformational change of the substrate-binding domain (closed form)
5. This shape clamps onto protein and locks it into the SBD allowing for protein folding
[molecular chaperones inhibit "bad" folding patterns]
6. ADP now "falls" off and new ATP binds (GrpE and BAG1 facilitate this exchange), converting
Hsp70 back into its open form and releasing the protein
