BS 161 Exam 3 - Questions & Expert Verified Answers
(Graded A+)
The cell surface reactor is in between the Right Ans - growth factor and the
changes in gene expression, RTK in example
changes in gene expression Right Ans - cellular response
what do all receptors have I common Right Ans - they all bind to specific
ligands and they all change shape after binding the ligand
a-helix is a type of Right Ans - secondary protein structure
when epinephrine interacts with amino acids found on different a-helices
within the receptor, it can cause a change in the position of helices within the
membrane. This would be a change in the ____ structure of the protein
Right Ans - tertiary
endocrine signaling Right Ans - signal travels through blood stream to
reach a target cell
neurons release neurotransmitters which travel a short distance to signal to
neighboring cells, this is an example of: Right Ans - paracrine
endocrine singling Right Ans - signal travels through the circulatory system
to receptor protein
why wouldn't a cell respond to a ligand Right Ans - the cell doesn't have a
receptor to bind to the ligand
which of the following describes the signal transduction for receptors Right
Ans - the activated intracellular receptor can bind to DNA; the activated cell
surface receptor binds to other proteins
some individuals are genetically male (XY) and produce testosterone but have
female external characteristics. What could eb the cause of this? Right Ans -
receptor is not present in the cell
,charged molecules cannot cross a Right Ans - lipid bi layer
which of the following is typically part of termination of G protein coupled
receptor pathways? Right Ans - cAMP is converted to AMP
which of the following signal mechanisms is a covalent modification Right
Ans - phosphorylation
what does phosphorylation do to the serine side chain Right Ans - it
changes a polar hydroxyl group to a charged phosphate group
How is the active G protein inactivated? Right Ans - the GTP is hydrolyzed
to GDP
what would happen if GTP were not hydrolyzed Right Ans - the G protein
would be active longer
what kind of protein is Ras Right Ans - G protein
how much cell division is occurring in adults Right Ans - cell division
occurs at a high rate in some cell types and rarely in others
When comparing the DNA content, the M phase cell has _____ the amount of
DNA when compared to the Interphase cell Right Ans - 2x
Histones are proteins that help compact DNA. the side chain from which
amino acid is likely favorably the backbone of DNA Right Ans - -ch2-ch2-
ch2-ch2-NH3+
human cells contain 46 chromosomes (22 identical pairs homologous
chromosomes) and the sex chromosomes.
the haploid number of chromosomes in humans is Right Ans - 23
in mitosis, human cells divide and produce daughter cells with Right Ans -
46 chromosomes
homologous chromosomes carry the same set of genes. the same genes of
different homologous chromosomes are called Right Ans - alleles
, if the sequence at the position marked 1, is 5'-CTC-3' what do you know about
eh sequence at other positions? Right Ans - position 2must have same
sequence and position 3 could have a different sequence
how does the amount of DNA and number of chromosomes vary across the
cell cycle? Right Ans - the amount of DNA varies but the number
chromosomes remains the same
which of the following could cause a cell to continue to have 10pg of DNA
Right Ans - if cytokinesis did not occur
when a steroid hormone binds to an intracellular receptor, what happens
after the receptor changes shape Right Ans - the receptor activates
transcription
intracellular receptor key points: Right Ans - 1. signal can cross plasma
membrane by simple diffusion
2. receptor is in cytoplasm
3. binding signal activates receptor which is also transcription factor
4. shortest of signaling pathways
when pathway is activated, the cellular response is cell division. what will
happen to cell division if signaling molecule (ligand) is absent, but the Ras
protein is always bound to GTP and why Right Ans - cell division would
increase because the Ras-GTPis the active form of signal transduction protein
for cell division
compared to cell in G1, the number of chromosomes in one cell ____ after the S
phase and. ______ after the M phase Right Ans - does not change; does not
change
what needs to happen in the cell to ensure the daughter cells have identical
genetic information Right Ans - each sister chromatid needs a spindler
fiber attached to kinetochore and sister chromatids needs to separate
what create a coherent explanation of how CDKs function Right Ans - CDKS
are controlled by protein/protein interaction and increasing the
concentration of cyclin protein will increase activity if CDK
(Graded A+)
The cell surface reactor is in between the Right Ans - growth factor and the
changes in gene expression, RTK in example
changes in gene expression Right Ans - cellular response
what do all receptors have I common Right Ans - they all bind to specific
ligands and they all change shape after binding the ligand
a-helix is a type of Right Ans - secondary protein structure
when epinephrine interacts with amino acids found on different a-helices
within the receptor, it can cause a change in the position of helices within the
membrane. This would be a change in the ____ structure of the protein
Right Ans - tertiary
endocrine signaling Right Ans - signal travels through blood stream to
reach a target cell
neurons release neurotransmitters which travel a short distance to signal to
neighboring cells, this is an example of: Right Ans - paracrine
endocrine singling Right Ans - signal travels through the circulatory system
to receptor protein
why wouldn't a cell respond to a ligand Right Ans - the cell doesn't have a
receptor to bind to the ligand
which of the following describes the signal transduction for receptors Right
Ans - the activated intracellular receptor can bind to DNA; the activated cell
surface receptor binds to other proteins
some individuals are genetically male (XY) and produce testosterone but have
female external characteristics. What could eb the cause of this? Right Ans -
receptor is not present in the cell
,charged molecules cannot cross a Right Ans - lipid bi layer
which of the following is typically part of termination of G protein coupled
receptor pathways? Right Ans - cAMP is converted to AMP
which of the following signal mechanisms is a covalent modification Right
Ans - phosphorylation
what does phosphorylation do to the serine side chain Right Ans - it
changes a polar hydroxyl group to a charged phosphate group
How is the active G protein inactivated? Right Ans - the GTP is hydrolyzed
to GDP
what would happen if GTP were not hydrolyzed Right Ans - the G protein
would be active longer
what kind of protein is Ras Right Ans - G protein
how much cell division is occurring in adults Right Ans - cell division
occurs at a high rate in some cell types and rarely in others
When comparing the DNA content, the M phase cell has _____ the amount of
DNA when compared to the Interphase cell Right Ans - 2x
Histones are proteins that help compact DNA. the side chain from which
amino acid is likely favorably the backbone of DNA Right Ans - -ch2-ch2-
ch2-ch2-NH3+
human cells contain 46 chromosomes (22 identical pairs homologous
chromosomes) and the sex chromosomes.
the haploid number of chromosomes in humans is Right Ans - 23
in mitosis, human cells divide and produce daughter cells with Right Ans -
46 chromosomes
homologous chromosomes carry the same set of genes. the same genes of
different homologous chromosomes are called Right Ans - alleles
, if the sequence at the position marked 1, is 5'-CTC-3' what do you know about
eh sequence at other positions? Right Ans - position 2must have same
sequence and position 3 could have a different sequence
how does the amount of DNA and number of chromosomes vary across the
cell cycle? Right Ans - the amount of DNA varies but the number
chromosomes remains the same
which of the following could cause a cell to continue to have 10pg of DNA
Right Ans - if cytokinesis did not occur
when a steroid hormone binds to an intracellular receptor, what happens
after the receptor changes shape Right Ans - the receptor activates
transcription
intracellular receptor key points: Right Ans - 1. signal can cross plasma
membrane by simple diffusion
2. receptor is in cytoplasm
3. binding signal activates receptor which is also transcription factor
4. shortest of signaling pathways
when pathway is activated, the cellular response is cell division. what will
happen to cell division if signaling molecule (ligand) is absent, but the Ras
protein is always bound to GTP and why Right Ans - cell division would
increase because the Ras-GTPis the active form of signal transduction protein
for cell division
compared to cell in G1, the number of chromosomes in one cell ____ after the S
phase and. ______ after the M phase Right Ans - does not change; does not
change
what needs to happen in the cell to ensure the daughter cells have identical
genetic information Right Ans - each sister chromatid needs a spindler
fiber attached to kinetochore and sister chromatids needs to separate
what create a coherent explanation of how CDKs function Right Ans - CDKS
are controlled by protein/protein interaction and increasing the
concentration of cyclin protein will increase activity if CDK
