Unit 1
What happens to a red blood cell in pure water?
It pops.
What does temporal summation at a postsynaptic neuron imply?
presynaptic neuron that is sending frequent EPSP
Which ion binds to troponin to trigger skeletal muscle contraction?
Calcium
How is most oxygen carried in the blood?
by binding to the heme group of hemoglobin
What is an anticodon, and where is it found?
A three-base sequence on tRNA that binds with mRNA
How is stimulus strength encoded by sensory neurons?
A stronger signal is translated to a higher frequency in action potentials
bigger stimulus = higher frequency in AP
AP = all or none --> same amplitude each time
Which neurotransmitter is released at the neuromuscular junction?
ACh
How does gas exchange between alveoli and blood occur?
simple diffusion
driven by concentration gradients without energy input, unassisted by membrane proteins
What is the complementary mRNA sequence?
CGATT
GCUAA
What happens to a neuron's membrane potential during depolarization?
It becomes less negative compared to resting potential.
What ions does the skeletal muscle ionotropic receptor allow through?
Sodium and Potassium
more permeable to Na+ than K+
=Na+ influx is larger than K+ efflux
=net depolarization
How is most carbon dioxide transported in blood?
mostly transported in plasma as bicarbonate
Which four elements make up ~96% of body mass?
carbon, oxygen, hydrogen, nitrogen
Describe the characteristics of graded potentials.
check picture
During which cardiac phase are all valves closed and ventricles in diastole?
isovolumetric relaxation
Which fluid compartment has the highest concentration of anionic proteins?
intracellular fluid (ICF)
What type of bond holds complementary DNA bases together?
hydrogen bonds
How does an excitatory postsynaptic potential (EPSP) affect the membrane?
short distance depolarization; opening of ligand-gated Na+ channels
The first heart sound occurs just prior to which phase?
isovolumetric contraction
If MAP drops and renin is secreted, which effects are likely?
If blood pressure drops low causing renin to be secreted:
GFR would decrease
NFP would decrease
Kidney perfusion would decrease