Practice Exam review BIO Flashcards
List some key characteristics of RNA Polymerase
- RNA Polymerase is only used in Transcription
- RNA polymerases have no editing function since RNA is a transient molecule and its information is not passed on to offspring
Deleting a nucleotide during transcription would result in__________
Deleting a nucleotide during transcription would result in a serious mutation called a frameshift mutation, which would completely destroy the protein’s amino acid sequence and structure
If a nucleotide is deleted during the transcription process this event would most likely lead to:
the destruction of the correct reading frame.
There is only one enzyme which can synthesize DNA
DNA polymerase
EXONS
Exons are not removed from the transcript; they are ligated together to form the mature mRNA
Rod cells
which are responsible for dim, black and white vision
NIGHT vision
**What tissues are part of the immune response **?
- The thymus is the site of T-cell maturation
- The spleen is the site of B-cell maturation and also filters antigens from blood
- Lymph nodes are sites of both B- and T-cell proliferation
Pancreas
The pancreas produces digestive enzymes, bicarbonate, and hormones
B lymphocytes are involved in a process called:
Humoral immunity.
- Humoral immunity refers to immunity through fluid; in this case, the blood. This is where B cells have their effect: They release antibodies into the bloodstream.
Cell-mediated immunity:
*** Cell-mediated immunity is the process that cytotoxic (Killer) T cells are involved in. **
Killer T cells kill “self” cells that are displaying abnormal antigen on MHC I. Helper T cells are activated by antigen displayed on MHC II, and secrete chemicals to help activate and stimulate the proliferationof killer T cells and B cells.
Passive immunity:
refers to an injection of antibodies which can act as a temporary supply and help fight off a disease until a person’s own immune system can start producing antibodies
The Complement system:
The complement system is a system of proteins and enzymes which, when activated, can cause cell lysis
Excess calcitonin in the blood would most likely result in which of the following abnormalities?
Abnormally dense bones
** Calcitonin reduces blood calcium levels through three processes: decreasing calcium reabsorption by the kidney, decreasing calcium absorption by the small intestine, and activating osteoblasts, which store calcium as bone. This last function increases bone density**
Under physiological conditions, which of the following amino acids is most likely to be found on the exterior of a body protein after folding is complete?
Hydrophilic (POLAR) residues prefer to face toward the protein exterior and are therefore likely to be found on the protein surface
ex) E- glutamate
What elements undergo H bonding?
FON
Cysteine residues form what bonds?
**Cysteine residues are close in space in a protein, the formation of a disulfide bond between them helps to stabilize the globular structure of the protein **
**Fatty acid synthesis **
Fatty acid synthesis will only be active if the cells have enough energy and are ready to build storage molecules, especially long term storage molecules.
Insulin
Insulin is released in response to elevated blood glucose and the glucose can be used for cellular respiration and storage
**glucagon **
glucagon is a hormone that liberates glucose from glycogen, raises blood glucose levels, and induces fat/triglyceride breakdown
Thyroid hormone
Thyroid hormone increases the basal metabolic rate of cells. This will increase the ATP consumption of the body and limit production of any long-term storage molecules
Cortisol
Cortisol is a stress hormone and will lead to lipolysis to increase ATP availability in stressful situations. It will inhibit lipogenesis
beta-oxidation occurs in what location
The mitochondrial matrix
Fatty acid synthesis takes place in______
** cytosol **
Where does Elongation and desaturation of fatty acids takes place?
**Elongation and desaturation of fatty acids takes place inside the **smooth ER **using separate enzymes.
Missense mutation
A missense mutation converts a codon for one amino acid into a codon for a new amino acid, resulting in a small change within the protein’s primary sequence, and an alteration (but usually not a total elimination) of the protein’s function
Nonsense mutation
A nonsense mutation creates a stop codon out of an amino acid codon, resulting in truncation of the protein and (usually) a loss of its function
Deletion mutation
A deletion mutation eliminates one or more base pairs, altering the reading frame and drastically changing the amino acid sequence of the protein
Diabetes insipidus is a condition in which an individual fails to produce antidiuretic hormone. If a person suffering from diabetes insipidus were to consume large amounts of a sugar-containing beverage, which of the following would most likely be observed after one hour?
An individual who cannot make ADH will be unable to reabsorb water from the collecting duct of the nephron, resulting in urine that is very dilute
Anti-Diuretic Hormone (ADH/ Vassopressin)
Released from: Posterior pituitary
Target: Kidney
Affect: water retention
if ADH is present, water can be reabsorbed from the urine, thereby concentrating the urine and preventing dehydration of the body.
Amphoteric
means that a molecule can act as either an acid or a base
Phospholipids
Phospholipids contain a backbone (usually glycerol) with two fatty acids and a phosphate group. The phosphate group can be linked to other polar groups.
triacylglycerides
Lipids that contain a glycerol backbone and three fatty acids are called triacylglycerides
aerobic conditions
the presence of free oxygen
anaerobic conditions
lack oxygen
If yeast cells were cultured under aerobic conditions would there be a greater number of cells than under anaerobic respiration?
Yes, because the cells have more ATP available to them for reproduction
The Gram staining in Gram-positive bacteria is due to the presence of:
peptidoglycan.
thick wall
stains purple
Gram-negative
stains pink
not thick wall
lactic acid is used to generate NAD+, it is only under what conditions?
lactic acid is used to generate NAD+, it is only under anaerobic conditions
What organelle would be most closely associated with exocytosis of newly synthesized secretory protein?
Golgi apparatus
Which types of protein are produced by the ribosomes of the rough endoplasmic reticulum?
Membrane-bound
Integral
Secreted
what affect to large proteins have in plasma?
Serve an important role in regulation of plasma volume. For example, reducing the amount of albumin, to below-normal levels would most likely have the effect of the movement of water from the bloodstream into the tissues with resulting swelling, due to reduced osmotic pressure.
what is true for all liquids?
A higher vapor pressure indicates a lower heat of vaporization.
Diabetes insipidus, a disease of ADH deficiency, can be caused by destruction or dysfunction of the supraoptic and paraventricular nuclei of the hypothalamus. One symptom of a person with this condition might be:
an inability to produce concentrated urine.
What happens in absence of ADH ?
- **would lead to an inability to concentrate the urine.
- Excreting a dilute urine would certainly increase plasma osmolarity, but this would not increase blood pressure.
- Plasma volume would tend to decrease due to the excess loss of water, and blood pressure would drop****
ADH has no effect on heart rate or blood glucose levels—do not confuse this disorder with diabetes mellitus
osteoblastic activity
causes new bone formation as calcium is reabsorbed into the bone, thus reducing calcium serum levels, which in turn causes increased PTH activity
PTH
PTH increases osteoclastic activity in order to release calcium into the blood
RNA polymerase differs from DNA polymerase III in that RNA polymerase:
RNA polymerase does not require a primer and it does not have exonuclease activity. RNA polymerase synthesizes RNA in the 5’ to 3’ direction, which means it must travel 3’ to 5’ on the template strand.
Retroviruses, which are a subclass of RNA viruses, are unique in that they contain:
RNA-dependent DNA polymerase.
What are K+ leak channels?
K+ leak channels are the channels primarily responsible for the negative resting membrane potential. They allow many positive ions to flow out of the cell (K+ moves down its gradient, to the outside of the cell).
if they are blocked, these positive ions would remain inside the cell, driving the membrane potential in the positive direction. –>DEPOLARIZATION
Purines
AG
Pyrimidines
CUT
