Midterm 1 Flashcards
The organelle that helps in calcium regulation in the cell is?
c) Ryanodine Receptor
d) Sarcoplasmic Reticulum
Which of the following are potential sources of energy in the cell
e) all of the above
e) glycogen, fat, protein, ATP
Fastest contracting fiber type in mammals is:
a) Type IIA
b) Type IIX
c) Type IIB
d) Type I
c) though only found in rats, humans fastest is IIx
TRUE / FALSE: Determining the number of mitochondria in a fibre is a definitive way of determining fibre type?
Why would a fibre stain dark during an oxidative enzyme histochemical stain?
a) It contains MHCI
b) it contains high levels of myoglobin
c) it contains a high number of mitochondria
d) it has an extensive capillary network
e) all of the above
c) contains a high level of mitochondria
With respect to the motor unit, how can muscle force be increased?
Recruit more Motor Units
Increase frequency of stimulation
Which source of ATP has the lowest capacity?
a) oxidative metabolism
b) high energy phosphate transfer system
c) stored ATP
d) anaerobic glycolysis
c) Stored ATP
What is the function of a transcription factor?
- transcribes DNA to produce mRNA to produce proteins
* specific binding to a section of DNA sequence that codes for proteins of interest
In the muscle, it would be preferable to:
a) generate new fiber
b) improve/repair existing fibers
c) both would be equally preferable
b) improve / repair existing fibers
An important transcription factor involved in promoting myoblast differentiation is?
c) Myogenin factor 5
e) All of the above
Which of the following is/are false about muscle nuclei (nuclei found beneath the sarcolemma)
a) there are approximately 100-200 per mm of muscle length
b) they have the same proliferative potential as satellite cells (they can divide)
c) the number of nuclei plays a major role in dictating fibre size
d) a and b are false
e) a b and c are false
b) same proliferative potential as satellite cells
What factor(s) is/are a major contributor to muscle strength?
a) fiber type contribution
b) muscle size
c) muscle activation
d) b & c
e) a, b & c
d) muscle size and activation
Name another major factor that could potentially influence muscle wasting during aging?
Given the negative consequences caused by the loss of type II fibers during aging, would it be preferable to type I fibers?
• Type I always activated - fatigue resistant unlike Type II
• Type I have smaller MU allowing for finer movements and finer tuning of muscle force (smaller gradients of force production)
• Type II require faster neural frequency stimulation to induce force summation, unlike Type I
Examining mRNA is important in many cases because?
a) there is a 1:1 relationship between mRNA and protein levels in the cell
b) mRNA levels could influence protein levels
c) provides us an indication of how transcription events are working in the cell
d) b and c only
e) a, b, and c
d) influence on protein levels and indicator of transcription events in the cell