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
What kind of molecule is lactose? How does it affect its entry in cell
Lactose, like other carbohydrates, is very HYDROPHILLIC
Hydrophilic molecules CANNOT diffuse across a membrane into the cell
What effect tdoes tryptophan have on repressor? What occurs as a result?
Tryptophan’s effect on the bacterial repressor protein is to bind to and activate it. When the repressor is activated, it binds to the operator region of the trp operon and turns off transcription of the genes in that operon.
Since these are genes for enzymes involved in the synthesis of tryptophan, binding of the repressor would result in a decrease in tryptophan synthesis
What is parallel processing ?
Parallel processing: describes the simultaneously processing of different aspects of a stimulus ( , instead of analyzing the pieces of a stimulus step-by-step)
What is the relationship between visual field and visual cortex?
left side of the visual cortex controls the right side of the visual field, and vice versa
What does carbonate look like?
CO3^2-
What does bicarbonate look like?
HCO3-
What is carbonic acid ?
H2CO3
What kind of salt is Na2CO3?
BASIC SALT b/c The carbonate ion (CO3^2-) from Na2CO3 is the conjugate base of bicarbonate (HCO3-) , which is itself weakly basic in aqueous solution
The most basic salt with have highest pH
What kind of salts are NaCl and AlBr3?
Both NH4Cl and AlBr3 are ACIDIC salts because both cations will interact with water to increase the [H+] in solution
How are amino acids catabolized (broken down) ? What processes can these molecules then enter?
Amino acids are catabolized via deamination into α-keto acids and ammonia. An α-keto acid formed from valine will be converted to pyruvate. Pyruvate can keep going through cellular respiration to generate CO2, H2O and ATP.
What can pyruvate be converted to?
Pyruvate can keep going through cellular respiration to generate CO2, H2O and ATP.
Pyruvate is converted into one acetyl-CoA (during which 1 NADH is made), and the acetyl-CoA would then generate three NADH and only one FADH2 as it cycles through the Krebs cycle.
Pyruvate can also enter gluconeogenesis to generate glucose
What cells are used to increase glucose levels when levels are too low?
Glucagon secreted by ALPHA cells will help increase glucose levels
which cells are used to decrease glucose levels when levels are too high?
Insulin secreted by BETA cells will help lower glucose levels down (when too high)
what occurs during the G1/S checkpoint phase for cell cycle ?
Checking the levels of nucleotides in the cell is part of the G1/S checkpoint since these building blocks are required for DNA replication
What occurs during the G2/M checkpoint of Cell cycle?
Before the cell divides, it must check the integrity of the genome it is passing to the daughter cells.
** This includes making sure DNA replication is complete**
Before the cell divides, mutations have to be repaired
What is the function of glycogen phosphorylase ?
Glycogen phosphorylase catalyzes the rate limiting step of glycogenolysis—the release of glucose-1-phosphate from glycogen via its action on terminal α(1→4) linkages.
hence glycogen phosphorylase cleaves alpha 1, 4 linkages between glucose molecules
What is the function of glycogen 6- phosphatase?
Glucose-6-phosphatase hydrolyzes glucose-6-phosphate, resulting in the release of a phosphate group and free glucose for export from the cell.
What is function of phosphoglucomutase?
Phosphoglucomutase is involved in both glycogenolysis and glycogenesis by interconverting glucose 1-phosphate and glucose 6-phosphate.
What is role of pyrophosphate?
Pyrophosphatases are members of the acid hydrolase family of enzymes that cleave diphosphate bonds.
What is the role of glucose-6-phosphatase ?
Glucose-6-phosphatase: enzyme that hydrolyzes glucose-6-phosphate, resulting in the release of a phosphate group and free glucose for export from the cell.
what happens when there is a deficiency of glucose 6 phosphatase?
When this enzyme is absent, glucose-6-phosphate, a product of the breakdown of glycogen in the liver, will remain trapped within the liver and will not pass into circulation.
As a result, some patients may be at an increased risk of hypoglycemia and require regular administration of exogenous glucose to meet metabolic demands.
What are the steps for embryogenesis ?
Fertilizatoin–> Blastualation (hollow ball) –> gastrulation —> Neural tube formation–> somite formation
What is the role of tight junctions ?
Tight junctions hold cells together and can form a SEAL so that fluid does not leak between cells
What do tight junctions NOT do?
iTight junctions do NOT however, form a junction between the cytoplasm of cells nor do they allow the transmission of action potentials
What event is necessary for forming metaphase plate ?
. Formation of microtubules is crucial for formation of the metaphase plate. Microtubules polymerize from the centrioles outward. They contact centromeres (to become kinetochore fibers) and “push” the chromosomes towards the center of the cell to form the metaphase plate.
what would happen if there is NO proper microtubule polymerization ?
Without proper microtubule polymerization, metaphase (and the rest of mitosis) CANNOT occur.
If mitosis cannot occur, then neither can tumor growth happen.
Why are microtubules necessary during prophase? What other events occur during prophase?
microtubules are also required during prophase in forming the mitotic spindle; however, some parts of prophase can still occur in the absence of microtubule formation (DNA condensation, loss of the nuclear membrane).
Does dephosphorylation or phosphorylation use Less energy ?
Phosphorylation uses LESS energy
When is creatine supplementation most effective?
Creatine supplementation is therefore most effective when performing short-term and high intensity tasks, such as sprinting
Describe what occurs in the phosphocreatine shuttle system?
The phosphocreatine shuttle system: allows transfer of high-energy phosphate bonds from the mitochondria to the sarcoplasm of a muscle cell: creatine kinase transfers a phosphate group from ATP to creatine in the mitochondria.
Phosphocreatine is then translocated to the sarcoplasm, and the phosphate group is transferred back to a molecule of ADP via a spontaneous reaction mediated by another creatine kinase.
What kind of side chain does amino acid Methionine have ?
A thioether group
What are the the photoreceptor cells of retina ?
. RODS and CONES are photoreceptor cells
What is the role of rod cells (eye) ?
Rods are the ones more sensitive to light, making them important for night vision.
What is the role of Cones (eye) ?
Cones are the cells responsible for detecting color and are the cells responsible for the defect involved in color blindness
What would happen if inner mitochondrial membrane became permeable to ions?
If the inner mitochondrial membrane became permeable to ions, then hydrogen ions would not need to go through the ATP synthase in order to re-enter the matrix. This would dissipate the proton gradient established by the electron transport chain, and decrease its potential to generate ATP
How many beta oxidation cycles will occur with 18 C?
18 divided by 2 - 1 = 8 beta oxidation cycles
How many acetyl CoA, NADH and FADH2 are produced for 18 C fatty acid in Beta oxidation
18 C FATTY acid:
8 beta oxidation cycles
-9 acetyl coA (18 c divided by 2)
-8 NADH
-8 FADH2
How many NADH, FADH2, and GTP produced for 1 acetyl coA in Krebs cycle? How many ATP for each of these ?
1 acetyl CoA :
- 3 NADH
-1 FADH2
- 1 GTP for each acetyl coA
ATP:
1 NADH = 2.5 ATP
1 FADH= 1.5 ATP
1 GTP = 1 ATP
calculate total number of NADH, FADH2, ATP, GTP, acetyl coa for 18 c
18 C :
8 Beta oxidation cycles :
each cycle equals 1 NADH and FADH2, hence
8 NADH and 8 FADH2
9 acetyl coA
(each acetyl coa, 3 NADH, 1 FADH2)
27 NADH
9 FADH2
Total ATP
8 NADH + 27 NADH = 35 X 2.5 = 87.5 ATP
8 FADH2 + 9 FADH2 = 17 X 1.5 = 25.5 ATP
Add all: 87.5 + 25.5= 122 ATP
122- 2 (subtract 2 since ATP —> AMP) = 120 ATP
