Test 5 review Flashcards
What is the process of apoptosis and what kind of machinery is used ?
Apoptosis occurs with proteases called cap spaces
process:
1. Initiator caspases cluster together and initiate apoptosis (
2. These initiator caspases can then activate effector caspases, which cleave proteins at aspartic acid residues; this triggers apoptosis
What occurs during phase 0 of an Action potential process in both cardiac and skeletal muscle ?
In both cardiac and skeletal muscle, as in neurons, the initial DEPOLARIZATION (Phase 0) is caused by the opening of voltage-gated Sodium channels. When the channels open, sodium flows into the cell down the gradient maintained as part of the resting membrane potential
What occurs during phase 2 of Action potential process in Cardiac cell?
Part of the cardiac action potential is the Opening of slow voltage-gated calcium channelsto create the PLATEAU in depolarization (Phase 2) When the voltage-gated calcium channels open, calcium enters the cell and can play a role in the contraction of the cardiac muscle.
What happens to sarcomere length during contraction ?
Sarcomere length DECREASES during each contraction
how do myosin and actin bind during contraction ?
myosin binds actin REVERSIBLY during contraction
What occurs in aerobic respiration and how many ATP is produced ?
Aerobic respiration includes glycolysis, the PDC, the Krebs cycle, and electron transport, to produce a total of 32 ATP per glucose (assuming the malate-aspartate shuttle is used to transfer the electrons from glycolytic NADH into the mitochondria).
What occurs during anaerobic respiration and how many ATP is produced?
Anaerobic respiration involves only glycolysis and fermentation of pyruvate to lactate or alcohol, to produce 2 ATP per glucose.
is anaerobic or aerobic respiration more efficient ?
AEROBIC respiration is More efficient since it uses LESS glucose to produce an equivalent amount of ATP (as anaerobic respiration)
What happens to PCO2 with a decreased ability to breathe out air
HIGHER amount of PCO2 in blood
What factors affection diffusion of the membrane?
The factors would include thickness of the diffusion barrier and the effective surface area.
What is the process of conducting an action potential across a synapse?
During the conduction of an action potential across a chemical synapse:
21. neurotransmitter is released by the presynaptic cell
2. it diffuses across the synapse, binds to receptors on the postsynaptic cell
3. opens ion channels on the postsynaptic cell depolarizes (or hyperpolarizes) the postsynaptic cell.
What happens to blood volume, urinary output and blood pressure when water reabsorption is reduced?
Reduced water resorption would tend to increase urinary output, decrease blood volume, and decrease blood pressure. subsequent increase in water reabsorption
What happens when there is an increase in ADH (antidiuretic hormone; aka vasopressin) ?
High levels of vasopressin (ADH) would increase water resorption and plasma volume (choice A is wrong).
What is ACTH and what happens if there is a ACTH tumor?
ACTH is the hormone that controls secretion of aldosterone (as well as cortisol) by the adrenal cortex.
An ACTH-secreting tumor will cause elevated secretion of aldosterone, increased Na+ reabsorption, and a subsequent increase in water reabsorption
What do Vmax and km represent?
Vmax : maximum reaction rate
Km is the amount of substrate required to get to ½Vmax
What is the role of catalase ?
Catalase inactivates peroxide and macrophages produce peroxides to kill bacteria.
If a bacterium makes catalase, it may be more resistant to macrophages.
What is the role of DNA Gyrase ?
DNA gyrase supercoils bacterial DNA The job of DNA gyrase is to continually introduce negative supercoils into the circular bacterial genome.
Which hormones are small hydrophobic molecules? How do they move through plasma membrane ?
Thyroid hormone, aldosterone, and cortisol are all small hydrophobic molecules that PASSIVELY diffuse through the plasma membrane to bind to receptors inside the cell in the cytoplasm and nucleus.
These receptors then regulate transcription, without the use of second-messenger system
Which hormone is hydrophilic and how does it work?
h A hydrophilic hormone like epinephrine, however, binds to cell-surface receptors and activates adenylate cyclase to make cAMP, a second messenger
differentiate between steroid hormones and amine hormones?
Note that in general, steroid hormones exert their effects by modifying transcription, while protein hormones utilize second-messenger systems.
What occurs in individual with trisomy?
an individual will have an EXTRA copy of a chromosome
What kind of cells occur during metaphase I?
During metaphase I, the developing gametes are still DIPLOID (separation of homologues has not yet occurred), so this individual would have the normal 46 chromosomes
What are the properties for titration curves on a graph
Titration curves are characterized by a sharp change in pH at the equivalence point (center)
Which level of protein structure is likely affected by confirmational change
TERTIARY Structure
conformational change in a protein is a change in the larger scale folding of a protein, with changes in the relative positions in space of amino acids located far from each other in the linear polypeptide chain.
The tertiary structure of a protein involves large-scale structure within a polypeptide chain that is stabilized by interactions between amino acids that can be distant from each other in the linear sequence;
What happens when repressor and allolactose bind? What happens if repressor becomes mutated
Binding to allolactose is required for inactivation of the repressor protein. If the repressor protein were mutated such that it could no longer bind to allolactose, it would never be inactivated (that is, removed from the operator; , and the genes in the lac operon would never be transcribed. This would be harmful to the bacteria, because they would be unable to utilize lactose as an energy source
