Cholesterol is most abundant in animal cell membranes (from amoebas to vertebrates) where it
A. promotes fluidity
B. strengthens the cell wall
C. causes heart attacks
D. forms ion channels
Answer: A
Biochemistry
- Certain enzymes, like those in the Glycogen Breakdown Cascade, are active only when phosphorylated. Suppose you wanted to produce a version of the enzyme that is constitutively active, i.e. active all the time? You can alter the gene and replace a certain:
- Protein Kinase A binds to the sequences RRGSE in substrate proteins, and transfers a phosphate from ATP to the Serine (S) in that sequence. A protein with the sequence RRGAE would be called what?
- What is mysterious about the K+ channel that requires an explanation?
- Glycolipids are membrane lipids which contain:
- When insulin signals ingestion of food, GLUT-4 receptors are:
- Calcium is kept low in the cytoplasm, but "spikes" of Ca+2 concentration function as effective signals. What protein detects the presence of Calcium ion?
- One of the second messengers in Protein Kinase C activation is quite polar. It is often known by its abbreviation:
- The voltage gated sodium channel in never cells has about how many transmembrane helices?
- The Acetylcholine Receptor is:
- Cholesterol is found in membranes of which?
- The Acetylcholine receptor is
- If a transmemberane protein admits a sodium ion along with a molecule of Glucose (assuming that the sodium levels inside the cell is low) then this is an example of:
- Several cofactors including Coenzyme A, FAD, and NAD have what in common?
- When [ATP] = 5mM, [ADP] = 4mM, and [AMP] = 1mM, the Atkinson Energy Charge Function has the value:
- When it is active, Protein Kinase C is:
- Which Phospholipase removes the polar head group along with the attached P?
- An uncompetitive inhibitor causes what apparent changes?
- If a given substrate has a high Km with an enzyme we usually assume
- What are the dimensions (units) of the turnover number - k2 or kcat?
- Which is correct?
- What is fluid in the fluid mosaic model?
- Which of these is a reducing sugar?
- Which of the following is NOT mediated by a 7TM protein?
- What is the value of the Atkinson's Energy Charge Function when [AMP] = 1 M, [ADP] = 2M, and [ATP] = 5M?