FL 6 - Bio/Biochem Flashcards
At a pH below their pI, proteins carry a net (positive/negative) charge; above their pI they carry a net (positive/negative) charge.
At a pH below their pI, proteins carry a net positive charge
At a pH above their pI they carry a net negative charge.
Why is it useful to use 3 pKa values when finding the isoelectric point?
IT IS NEVER USEFUL.
Isoelectric point will always be found by averaging only 2 pKa value. For an uncharged amino acid, it is simply the average of the amino group and carboxy group.
for acidic amino acids, the pI is the average of the two lowest pKa values; for basic amino acids, the pI is the average of the two highest pKa values. Be careful to avoid averaging all three values given; the pI is always the average of two, not three, pKa values.
A single nucleotide substitution that codes for an altered protein product without also altering the length of the protein is likely a ________ mutation.
A single nucleotide substitution that codes for an altered protein product without also altering the length of the protein is likely a missense mutation.
This mutation type almost always results in a radically different protein product. A ______ mutation involves insertion of a premature stop codon. Such a change would almost certainly shorten the length of the translated protein.
This mutation type almost always results in a radically different protein product. A nonsense mutation involves insertion of a premature stop codon. Such a change would almost certainly shorten the length of the translated protein.
_______ mutations do not alter the function of the protein produced because of the degeneracy of the genetic code.
Silent mutations do not alter the function of the protein produced because of the degeneracy of the genetic code.
__________ are responsible for the myelination of axons in the peripheral nervous system.
Schwann cells are responsible for the myelination of axons in the peripheral nervous system.
While _________ are indeed responsible for the myelination of neurons (corresponding to faster signal transduction), these are only responsible for myelination of neurons from the central nervous system
While oligodendrocytes are indeed responsible for the myelination of neurons (corresponding to faster signal transduction), these are only responsible for myelination of neurons from the central nervous system
Interneurons connect motor and sensory neurons, and are found exclusively in the _______ nervous system.
Interneurons connect motor and sensory neurons, and are found exclusively in the central nervous system.
________ primarily play a role in the immune system and defense of neuronal cells in the central nervous system.
Microglia primarily play a role in the immune system and defense of neuronal cells in the central nervous system.
_________ is an amino acid neurotransmitter, which necessarily utilizes cell surface receptors that are integrated into the plasma membrane.
Glutamate is an amino acid neurotransmitter, which necessarily utilizes cell surface receptors that are integrated into the plasma membrane.
A higher Kd is (more/less) likely to dissociate
A higher Kd is more likely to dissociate
What is a vertical pattern of inheritance?
Vertical patterns of inheritance are typical in dominant traits where the phenotype is very likely to show up in every generation. A vertical pattern of inheritance for a recessive trait is possible if the trait is extremely common in the population.
The GI system develops from the ________ layer
The GI system develops from the endodermal layer.
The endoderm is basically responsible for the interior linings of the body, including the linings of the gastrointestinal system, the pancreas and part of the liver, the urinary bladder and part of the urethra, and the lungs.
What is the term for the primitive gut (the cavity in the gastrula)?
Archenteron
What is the archenteron?
The archenteron is the primitive gut (the cavity in the gastrula)
True or False:
Antigen presentation is a function of macrophages.
True. Antigen presentation is a function of macrophages.
True or False:
Cytokine release is not a function of macrophages.
FALSE.
Cytokine release IS a function of macrophages.
True or False:
Opsonization is a function of macrophages
False.
Opsonization is the process by which antibodies bind to and recognize antigens on the surface of a pathogen. The antibodies then attract macrophages to phagocytose the invader.
Diabetes mellitus results from the dysregulation of insulin. Type ___ diabetes is caused by an autoimmune attack on the pancreatic beta cells, which produce insulin. Type ___ diabetes results from a more gradual breakdown of the degree to which target cells respond to insulin signaling. This loss of responsiveness is termed insulin insensitivity. Individuals with type __ diabetes are dependent upon the administration of exogenous insulin, because they no longer produce the hormone in sufficient quantity to properly regulate blood glucose levels. Patients with type __ diabetes are generally initially treated with dietary modifications and/or anti-hyperglycemic medications, but they may eventually require insulin treatment as well.
Diabetes mellitus results from the dysregulation of insulin. Type 1 diabetes is caused by an autoimmune attack on the pancreatic beta cells, which produce insulin. Type 2 diabetes results from a more gradual breakdown of the degree to which target cells respond to insulin signaling. This loss of responsiveness is termed insulin insensitivity. Individuals with type 1 diabetes are dependent upon the administration of exogenous insulin, because they no longer produce the hormone in sufficient quantity to properly regulate blood glucose levels. Patients with type 2 diabetes are generally initially treated with dietary modifications and/or anti-hyperglycemic medications, but they may eventually require insulin treatment as well.
A person with increased levels of insulin most likely has a decreased level of _________
A person with increased levels of insulin most likely has a decreased level of blood glucose
This question asks us to determine what best explains the effectiveness of bile in lipid digestion. We know that bile works to form micelles and is able to do this because it has both ________ and _________ portions. This is what “__________” means.
This question asks us to determine what best explains the effectiveness of bile in lipid digestion. We know that bile works to form micelles and is able to do this because it has both hydrophobic and hydrophilic portions. This is what “amphipathic” means.
Lack of bile acids could lead to deficiency in which of the following?
- Cholesterol
- Glucose
- Vitamin K
- Glycine
This question is asking us to determine which of the four options is fat-soluble˜ and thus will be taken up from the small intestine with the help of bile. We should know that vitamin K is a fat-soluble vitamin (as are A, D, and E) and thus its absorption depends on fat’s absorption from the small intestine.
In the plasma membrane, cholesterol increases fluidity at _____ temperatures and reduces fluidity at _____ temperatures, in both cases by moderating the tendency of phospholipids to clump together (at ____ temperatures) or to diffuse through the membrane (at ____ temperatures).
In the plasma membrane, cholesterol increases fluidity at low temperatures and reduces fluidity at high temperatures, in both cases by moderating the tendency of phospholipids to clump together (at low temperatures) or to diffuse through the membrane (at high temperatures).
