Biological Sciences Flashcards
The activated form of Vitamin D stimulates the absorption of _______ into the blood through the small intestine.
calcium
Parathyroid hormone increases the activity of ________, which break down bone cells to increase calcium levels in blood plasma.
osteoclasts
Vitamin C promotes bone ________ and is required for the synthesis of the bone matrix, lowering the concentration of calcium in the blood plasma.
Formation
________ reduces calcium reabsorption by fine-tuning (small changes). High levels of this are found in the blood when calcium levels in the plasma are high.
calcitonin
Bone reabsorption occurs when levels of calcium in the blood plasma are ______.
Low
What would result from the complete removal of the parathyroid glands?
severe neural and muscular problems due to deficiency of calcium in the plasma
condition of low blood calcium resulting from the lack of parathyroid hormone
causes increased neuromuscular excitability due to increase in membrane potential which is usually partly kept in balance w/ extracellular calcium
usually kills patients through respiratory muscle spasms
hypocalcemia
what explains if a product is the result of a kinetic control?
its reaction profile has a lower energy of activation
product is formed faster than the thermodynamically controlled product bc the energy of activation is lower.
kinetically controlled product
a compound (product) produced under equilibrium conditions that is more stable than other products
thermodynamically controlled product
what is the hybridization of the carbonyl carbon in cyclohexanone?
sp2
carbonyl carbon bonded to 3 other atoms, creating 3 hybrid orbitals
what endocrine disorder could cause hypertension that could not be remedied w/ a physiologically normal kidney?
excess aldosterone
Aldosterone is a hormone release by the _______. It increases the absorption of __________ by the kidneys and leads to an increase in ________.
adrenal glands
sodium and water
blood pressure
What mechanism is most likely responsible for increased urine output (induced by hypertension)
increased glomerular filtrate rate
an increase to the systemic blood pressure would initially increase the ___________, which would increase glomerular filtration rate.
glomerular capillary blood pressure
solutes and water are reabsorbed in the ________ after filtration by the kidneys
renal tubules
reduced flow of blood through the renal arteries would cause a decrease in _________
glomerular blood pressure
system in the kidneys that increases the amount of sodium and water that is reabsorbed by the kidneys
increases blood volume and pressure
renin-angiotensin system of hormones
Equation: Blood Pressure
P = cardiac output x vascular resistance to flow of blood (P = CO * VR)
Enhanced activity of what basic muscle type would be most likely to cause hypertension by causing vasoconstriction?
Smooth muscle (in blood vessels)
What eukaryotic organelle is involved in the synthesis of antibody proteins?
Endoplasmic reticulum (Note: antibodies are secreted proteins translated by ribosomes on the rough ER)
The most effective way to remove triethylamine would be to extract the reaction mixture with aqueous ________ to make it water soluble.
HCl (hydrochloric acid);
Triethylamine is most soluble in an ________
organic solvent
T/F: The most stable conformation for an organic compound is one in which the largest substituent groups are in the axial position.
False; Largest (highest priority) substituent should be in the equatorial position in the most stable chair conformation
Filtration of uric acid in the kidney takes places in the _______
glomerulus
Region of the nephron where filtrate is formed as fluid passes from the glomerular capillaries through the glomerular membrane and into Bowman’s capsule.
glomerulus
what is the filtering unit of the kidney?
nephron
“cell eating”
requires the cell change shape dramatically as it surrounds and engulfs large extracellular particles
phagocytosis
one of the cytoskeletal elements that helps determine cell shape
ability to disassemble and reorganize
microtubules
two purines (nucleic acids)
guanine
adenine
3 pyrimidines (nucleic acids)
uracil
thymine
cytosine
place on an enzyme where a molecule that is not a substrate can bind
changes the shape of the enzyme and affects reactivity
allosteric site
binding site on an enzyme for a substrate
active site
which animal would primarily excrete nitrogenous waste in the form of uric acid? (uric acid - nontoxic, does not require much water for excretion)
flying bird
how many stereogenic centers does triacylglycerol have when it reacts w/ 3 different fatty acids?
1
only Carbon 2 is attached to 4 different groups
General formula for this type of molecule: R(n)–CO2H
fatty acid
How could saponification of triacylglycerol result in 4 different fatty acid salts?
one of the fatty acid salts was unsaturated and a small percentage isomerized under the reaction conditions
(i.e. one of the R groups contained a C–C double bond)
how many equivalents of sodium hydroxide is required to completely saponify triacylglycerol?
3 equivalents; 1 OH- is needed to hydrolyze 1 ester linkage for each of the 3 fatty acid chains
solubility properties of fatty acid salts
can partially dissolve in polar and nonpolar media
- Long, hydrocarbon chain soluble in organic solvents
- Carbonate salt (R–CO2- Na+) soluble in polar solvents (water)
structure is a polar head group (i.e. carboxylic acid) and long hydrocarbon tail
partially soluble in polar and nonpolar solvents
fatty acid
What is produced by the pancreas for the digestive system?
Proteolytic enzymes (trypsin, chymotrypsin, carboxypeptidase)
The presence of what organelle in fungi clearly marks it as a eurkaryote?
Mitochondria
3 proteolytic enzymes produced by the pancreas and activated in the small intestine
trypsin
chymotrypsin
carboxypeptidase
T/F: Prokaryotes have ribosomes
True
T/F: Prokaryotes can undergo sexual reproduction
True
First step in hydrolysis reaction
protonation of carbonyl oxygen (making carbonyl carbon more positive for nucleophilic attack)
from which germ layer do the heart and blood vessels differentiate?
Mesoderm
most effective way to increase the amount of water lost through the skin
raising environmental temperature
all chromosomes except the sex chromosomes
autosomes
two neighboring groups of the same organism are considered different species if _______
they do not interbreed to produce fertile offspring
a trait would evolve by natural selection if ________
individuals possessing that trait produce more offspring than individuals without that trait (passing on the advantageous phenotype)
*Most likely if the individual has multiple offspring so the trait becomes a significant portion of the gene pool
Within a sarcomere, the _________ lengths remain stable and do not change during muscle contraction because one end is anchored to the Z line
microfilament
It is likely that the rate at which viral particles are can be expelled from the cell depends on the _________
rate of microtubule polymerization (as the plasma membrane changes shape)
How many genotypically different kinds of a haploid cell can be produced ?
2^n
n = number of different traits involved in cross (3 traits, 2^n = 2^3 = 8)
What occurs in Mitosis but NOT Meiosis I in animals?
splitting of centromeres during anaphase
During anaphase I, ____________ are separated, each consisting of two sister chromatids connected at a centromere
homologues chromosomes
In eukaryotes, transcription of DNA and RNA occurs in the _____
nucleus
In eukaryotes, translation of proteins occurs in the ____
cytoplasm (on ribosomes)
