MCAT Biology Flashcards 2
(494 cards)
Which enzyme unwinds the double helix?
DNA helicase
saturation kinetics
dynamics of enzyme reaction speed… rate limited by enzyme concentation.
Three types of hormones
peptide, steroid, tyrosine derivatives
steps in bacterial infection
inflammation, macrophages and neutrophils engulf bacteria. Interstitial goes into lympathic system and lymphocytes are in lymph nodes. Macrophages present antigens to B lympocytes. B lymphocytes use helper T cells to differentiate into memory and plasma cells. plasma cells make antibodies which go into blood and attack bacteria. Memory cells are for secondary response.
hemoglobin
4 polypeptide subunits, each with a heme group–with iron in the center. Each can combine with one O2, forming oxy hemoglobin. cooperativity, a cascade effect.
MINERALS
inorganic elements that exist in the form of ions inside and outside the cell; establish electrochemical gradients, act as co-factors to enable protein function, and form matrix compounds in bone and else where
PROTEINS
organic compounds made up of long chains of amino acids
lacteal
A capillary network and a lymph vessel where nutrients are absorbed.
Replication Fork
Replisome attach on the chromosome at this location
DNA’s four nitrogenous bases
Adenine and ThymineGuanine and Cytosine
Noncompetitive inhibitors
bond to enzyme at nonactive site, change its shape to make it less effective. Cyanide is example.
human growth hormone (hGH)
made: anterior pituitaryeffects: all body cellsaction: stimulates growth, increasing protein production
venules, veins
veins contain much more blood by volume than arteries. Blood slowest in capillaries, next slowest in veins. Veins have valves to prevent backflow.
ELECTROSTATIC FORCES
the forces between particles that are caused by their electric charges
Promoter
A spot on the DNA that tells RNA polymerase where to begin transcription
specific peptide hormones
- anterior pituitary: FSH, LH, ACTH, hGH, TSH, Prolactin2. posterior pituitary: ADH, oxytocin3. parathyroid: PTH4. pancreatic: glucagon, insulin
NON-COMPETITIVE INHIBITION
does not attach to the active site instead it changes the shape of the enzyme so the substrate doesn’t fit as well, cannot be overcome with substrate concentration
ENZYME SPECIFICITY
each enzyme must be tailored made for one reaction, which gives the cell more control in regulating chemical reactions
ANAEROBIC RESPIRATION
the release of energy from glucose or another organic substrate in the absence of Oxygen
Difference between endocrine and exocrine glands.
exocrine release enzymes to external environment through ducts, ie sweat, oil, digestive stuff.endocrine releases directly into body fluid.
UNSATURATED FATTY ACIDS
the carbon chain has at least one double bond; lower melting point
oxygen saturation of hemoglobin depends on:
lower O2 affinity if high CO2 pressure, low pH (high H+), high temperature, BPG.
What is being removed from a deoxynucleotide triphosphate as each nucleotide is added to the new strand?
a removal of a pyrophosphate group
The gene for triose phosphate isomerase from maize (a corn plant) spans over 3400 base pairs of DNA and contains eight introns and nine exons. Which of the following would most likely represent the number of nulceotides found int eh mature mRNA after post
A is correct. Introns are remove from the primary trancript during posttransciptional processing. The number of nucleotides in the mature mRNA would have to be less than the number of base pairs of the gene.