Weekly Quiz 3 Flashcards
Assume a growth factor from outside a cell tells the cell to divide. The growth factor cannot diffuse through the plasma membrane and there are no transport proteins for that growth factor. What can you deduce about the growth factor receptor?
The growth factor receptor must be at least partly exposed to the fluid outside a cell.
The growth factor receptor must be connected to the inside of the cell.
The growth factor receptor must change shape when it binds to the growth factor.
When treating type 1 diabetes mellitus with insulin injections, what is the role of a glucose meter?
A glucose meter serves as a sensor in a negative feedback loop
If a concentration gradient is held constant, what is the most direct way to change the rate of osmosis across a cell membrane?
By changing the concentration of aquaporins in cell membranes
The portion of a cell membrane that forms the core (inside) of a lipid bilayer consists primarily of
Lipid
Mitochondria are most closely associated with
ATP Synthesis
The primary purpose of a buffer is to
Maintain the hydrogen ion concentration of a solution
The production of mRNA from a gene is called
Transcription
By which of the following methods does a cell control the rate of a chemical reaction?
By separating reactants from each other
Through the controlling the activity of enzymes
Sodium is moved from the inside of a cell to the outside of a cell by
Active transport
Glucose moves across the plasma membrane of a fat cell by
Facilitated diffusion
In human cells, a concentration gradient usually pushes potassium
Out of a cell
Humans have proteins that change shape in the presence of blood glucose.
True
How would adding acid to a non-buffered solution be most likely to affect protein structure?
Adding acid would disrupt the secondary and tertiary structure of the protein
If blood sodium dropped to dangerously low levels, cells in the body would
Swell and possibly pop
If a red blood cell is placed in a very dilute solution, what will happen
The cell will burst
When treating type 1 diabetes mellitus with insulin injections, where would we find the control center in the feedback loop?
Our brain
Transcription is the name for a process in which
A DNA template is used to form a complimentary strand of messenger RNA
Sources of chemical potential energy in the body include
Carbohydrate
Protein
Insulin receptors are glucose transporters
False
Moving sodium out of a cell
Requires the input of energy
If all GLUT4 transporters were destroyed, would injected insulin lower blood glucose?
No
A box of dried pasta can sit on the shelf indefinitely without breaking down, but when we eat the pasta, starch is broken down into water and CO2. Energy stored in the bonds is released. The reason pasta breaks down in our bodies is that
Enzymes in our bodies lower the amount of energy required for chemical reactions to move forward
How do forces act on sodium in resting cells?
Electrical gradient pushes in; concentration gradient pushes in
When blood glucose climbs, the sensor for the change is in the
Pancreas
If pancreatic beta cells are destroyed, will injected insulin lower blood glucose?
Yes
In type 1 diabetes mellitus, which of the following are compromised?
The sensor
The control center
Enzymes
Lower the activation energy required for a chemical reaction to occur
In type 2 diabetes mellitus, which component(s) of the insulin feedback loop is/are first disrupted?
The effector
Ribosomes are most closely associated with
mRNA translation
Protein synthesis
From rest, if we allow only potassium to cross a cell’s membrane, the cell would get
More negative
Where does gene transcription occur in a cell?
The nucleus
Ions moving down their electrochemical gradient
Release potential energy
When blood glucose climbs, an effector that helps the body return to homeostasis is located in the
Skeletal muscle
Glucose does not simply diffuse through a cell’s plasma membrane because
Glucose is polar, but a cell’s plasma membrane is not
In resting human cells, an electrical gradient pushes potassium
Into a cell
Translation is the name for a process in which
An RNA template is used to assemble proteins from amino acids
The production of a protein from mRNA is called
Translation
A gene provides instructions for the
The primary structure of the protein
Osmosis refers to
The diffusion of water
Do humans maintain blood glucose homeostasis?
Yes
