Chapter 1: Flashcards
(24 cards)
In terms of nutritional requirements, a bacterium must be grown in an environment with:
All of its nutritional requirements, often several types of amino acids. But we must have ALL of them, not just one, for growth to occur.
If a bacterium grows on the following plates of amino acids, what is a major nutritional requirement for the organism:
Plate 1: Alanine, cysteine, methionine, and valine (GROWTH).
Plate 2: Alanine, cysteine, proline, and valine (GROWTH).
Plate 3: Alanine, tyrosine, proline, and valine (NO GROWTH).
Plate 4: Alanine, cysteine, proline and tyrosine (NO GROWTH)
Cysteine and valine would be vital nutrients for the cell, because growth only occurs when BOTH of the amino acids are present.
You are performing an experiment to test the efficacy of antibiotics against two microbes, X and S. A highly selective antibiotic would show:
a. Growth of both organisms on an antibiotic plate.
b. Large growth of microbe X and minimal growth of microbe S.
c. No growth of either organism.
d. Free growth of microbe S, and no growth of microbe X.
d - Free growth of microbe A, and no growth of microbe X.
A selective antibiotic would target a specific bacterium, while a non-specific antibiotic can target many species simultaneously.
For bacteria X and R, there are 3 antibiotic options. Bacteria X is pathogenic, while R is involved in the microbiome. Antibiotic #1 kills bacteria X but not R. Antibiotic #2 kills bacteria X and R. Antibiotic #3 kills bacteria R but not X. A patient who is experiencing infection symptoms should be treated with:
The patient should be treated with antibiotic #1 - because it will kill the pathogenic bacteria (X), but not harm our microbiome’s healthy bacteria (R).
All of the following are involved in directing proteins to their final location in the cell EXCEPT:
- The amino acid sequence of the protein.
- Vesicles.
- Lysosomes.
- Endoplasmic reticulum.
Lysosomes are small, spherical, membrane-enclosed bodies that contain hydrolytic enzymes. These are used to destroy cellular waste.
How does the amino acid sequence of a protein play a part in determining the protein’s final location?
The Golgi apparatus and endoplasmic pack and sort proteins based on their amino-acid sequence.
How do vesicles play a part in determining the final destination of a protein?
Vesicles transport proteins across the cytoplasm and move proteins toward their final destination. These can be moved by motor proteins on the microtubules (like dynein to the negative end, and kinesin to the positive end).
How does the endoplasmic reticulum play a part in determining the final location of a protein?
The endoplasmic reticulum is the primary site of protein folding and beginning sorting.
Function of the nucleus:
Storage of DNA.
Function of the mitochondria:
Energy production.
Function of the smooth endoplasmic reticulum:
Lipid production and detoxification.
Function of the rough endoplasmic reticulum:
Protein production, in particular for proteins to be exported out of the cell.
Function of the Golgi apparatus:
shipping station - protein modification and export.
Function of the peroxisome:
waste removal, Lipid destruction - contains oxidative enzymes.
Function of the lysosome:
Protein destruction by hydrolytic enzymes.
The nucleolus is a:
a. A subspace in the nucleus.
b. An organelle in the nucleus.
c. The site of ribosome synthesis.
d. A membrane-bound structure.
TRUE -
a - A subspace in the nucleus.
c. The site of ribosome synthesis.
FALSE:
b - An organelle in the nucleus (is not membrane bound so can’t be)
d. A membrane-bound structure - No.
The process by which folded proteins are tagged by the endoplasmic reticulum and sent to the Golgi apparatus for export:
a. Amine addition.
b. Deglyceraldehyde.
c. Glycosylation.
d. Proteination.
c. glycosylation.
Why do all proteins created by the rough ER get exported to the cell membrane or outside of the cell?
Where are lipids and steroids produced?
a. Golgi apparatus.
b. Rough ER.
c. Mitochondria.
d. Smooth ER.
Smooth ER.
You are studying the metabolism of an alcoholic fruit punch product, to ensure its safety before placing it on public markets. The drink contains high levels of the sugar at very low calories, making it appealing to the health concious consumer. The following organ will produce an excess of which organelle to detoxify this product from the blood stream:
a. Kidney; Rough ER.
b. Intestine; mitochondria.
c. Liver; smooth ER.
d. Stomach; lysosomes.
c - Liver; smooth ER.
The smooth ER is the organ primarily responsible for detoxification.
What are the 4 paths that the Golgi apparatus will send a packed protein to be exported to?
- Cytosol - for proteins that enter the Golgi by mistake.
- Membrane proteins - often protein channels or cell identifiers.
- Secretion - Act on other parts of an organism outside of this specific cell (think steroidal hormones), these need to accumulate before being released.
- Lysosomes - Where hydrolytic enzyme proteins will be sent.
Lysosomal enzymes:
a. Are constantly active, and can be released upon any specific trigger.
b. Will cause lysis of the surrounding organelle.
c. Can only become active in a pH of 5 or lower, as a safety mechanism.
d. Contain glycolipids that stabilize the cell.
c - can only become active in a pH of 5 or lower, as a safety mechanism. This is because most of the cell will have a pH of 7.
A loss-of-function point mutation has occurred on a locus that encodes for peroxisomal proteins. This occurred due to random mutation, unassociated with a mutagenic substance. You want to investigate the broad consequences of this, and find that:
a. The cell will accumulate reactive oxygen species, causing oxidative stress.
b. The cell will lack lipids and steroids over time, causing dysfunction of metabolism.
c. The cell will lose the ability to sort proteins for proper export.
d. The production of ATP will be significantly reduced.
a - The cell will accumulate reactive oxygen species, causing oxidative stress.
This is because the peroxisome has two function: destruction of lipids, and protection from reactive oxygen species.
