BIOL1130 Lecture Notes - Lecture 9: Methionine, Start Codon, C-Terminus

13

Which of the two major categories of the chemical reactions in photosynthesis is oxygen the INDIRECT product?

A

Glycolysis

B

Oxidative phosphorylation

C

Both light and dark

D

Light independent phase (LIP)

E

Light dependent phase (LDP)

14

You have a stomach flu characterized by vomiting. Which of the following systems is most responsible for the food in your stomach going the wrong way, e.g. vomiting? (Disregard this question and answer choice B)

A

Cardiac Muscle in the large intestine as discussed in class.

B

Smooth muscle in the gastrointestinal tract

C

Smooth muscle in the blood vessels

D

Skeletal muscle in the intestine

15

Proteins are made from which of the following smaller sub units?

A

Nucleotides

B

Amino acids that cannot enter the blood stream and go to cells

C

Monosaccharides

D

Fatty acids

E

Amino acids which can form new protein

16

Carbohydrates are digested in the gastrointestinal system into which of the following substances that is the smallest structure?

A

Polysaccharides that are produced by glucagon

B

Monosaccharides that are produced by insulin

C

Monosaccharides

D

Polysaccharide

17

Which of the following biomolecules has the longest digestion time? In other words, how long does it take for the biomolecule to be catabolized?

A

DNA

B

Lipid

C

Carbohydrate

D

Protein

18

You are sunburned after a long day at the beach. Which one is not an example of UV damage to your skin cells?

A

A mutation can occur in your ovaries

B

A mutation can occur in skin cell DNA that can lead to errors in transcription.

C

Errors can occur during DNA replication.

D

UV light can cause mutations in DNA of skins cells.

E

Thymine bases in your skin DNA bond with each other instead of across the double helix

19

This region, the ______________ (a) tells RNA polymerase where to bind to DNA while this region, the ______________ (b) tells RNA where to start transcription.

A

(a) promoter, (b) open reading frame

B

(a) start codon, (b) methionine

C

(a) promoter, (b) start site

D

(a) start site, (b) promoter

20

The genetic code is used to translate ______________ into ______________.

A

lipids, nucleotides

B

nucleotides,carbohydrates

C

nucleotides, lipids

D

nucleotides, amino acids

E

nucleosides, amino acids

21

Transcription of a gene has just completed. What are the next steps (in the correct order) to complete expression of that gene?

A

RNA polymerase makes a copy of DNA into mRNA.

B

mRNA is translated in the nucleus and ribosomal RNA moves into the cytoplasm.

C

Gene expression is completed after transcription.

D

mRNA moves into the cytoplasm and with tRNA they interact to form protein

E

Translation machinery moves into the nucleus and mRNA is translated into protein.

22

How is it that a mutation in DNA stored inside the nucleus of a cell can cause a disease affecting multiple organs?

A

This remains an unanswered question in science that scientists are still trying to figure out.

B

The mutated DNA is expressed in multiple cells through the process of transcription and translation, and the altered protein causes the disease wherever the DNA was expressed.

C

The mutated DNA is expressed in one cell and the altered protein travels to multiple organs to cause disease.

D

The mutated DNA is expressed and the mRNA takes the mutated information to other cells where the altered protein is made to cause disease in that organ.

23

The advantage of sickle cell anemia is which of the following?

A

It decreases the amount of oxygen in the blood cells so that mosquitoes carrying malaria will live

B

It decreases the amount of oxygen in the blood cells so that mosquitoe's blood form will die.

C

It allows the blood vessels to decrease the amount of blood going to the toes and feet.

D

There is none.

24

Which of the following is a purpose of cell division?

A

Cell reproduction

B

Growth

C

Repair

D

All of these

Class 6: Viruses (and Cells, continued)


Making connections: viruses and microbes Match the cell biology concept (on page 1) with an important application of that concept (on page 2). Then answer the follow-up questions at the bottom of page 2.


Cell Biology concepts
1. Bacteria that cannot construct new cell wall material become fragile and break down.
2. During influenza infection, the viral enzyme neuraminidase is required to release new viruses from the host cell in which they were made. Once released, the new viruses can infect many additional cells.
3. Thermus aquaticus is a bacterium found in hot springs and can live at temperatures up to ~80°C (175°F). It has adapted so that its enzymes are most functional at the elevated temperatures, compared with many organisms’ enzymes that function best ~37°C (98°F).
4. Until the isolation and investigation of retroviruses, scientists thought that RNA could be copied from DNA, but DNA could not be copied from RNA. Research on this class of viruses led to an update to this “Central Dogma” of biology.
5. Some bacteria have adapted, so that the enzymes involved in making cell wall materials have a slightly different shape and can no longer be bound by certain drugs.
6. Rhizobia are bacteria that colonize the roots of certain plants (legumes, including beans and peas). The host plant benefits from the prokaryotes’ ability to “fix” nitrogen, converting N2 from the atmosphere into a form that is usable by the plant.
7. Many species of bacteria contain the enzyme cellulase. More than 10 billion such bacteria and other symbiotic microbes may be found in a single milliliter of material from inside the digestive system of ruminant mammals.
8. Fungi, including those that cause athlete’s foot, use ergosterol to maintain healthy membranes. Animal cells do not make ergosterol, they use a similar lipid – cholesterol.
9. During retrovirus infection, a DNA copy is made of the virus’s RNA genome. A cut is made in the host cell’s DNA and the DNA copy of the viral genome is pasted into the host chromosome by a viral enzyme called integrase.
10. Prokaryotic cells contain smaller ribosomes (“70S” ribosomes) than eukaryotic cells (“80S” ribosomes). Both types of ribosomes synthesize proteins, but the macromolecules they use to do it are somewhat different.



2
Applications
_______ Oseltamivir, also called Tamiflu, binds and inhibits the viral protein neuraminidase.
_______ Clotrimazole is a drug that is used to treat certain infections. It interferes with synthesis of ergosterol, a lipid involved in phospholipid membranes.
_______ Penicillin is a drug that interferes with synthesis of peptidoglycans (these are biological molecules that are part protein and part carbohydrate) that are present in certain cell walls.
_______ HIV is often treated with several drugs that inhibit different parts of the viral replicative cycle. Raltegravir is an example of a drug that interferes with the integration of viral genes into the host cell’s chromosome.
_______ Cows, like other vertebrates, lack the ability to breakdown cellulose. Yet they are able to live on a diet of grass and other vegetation high in cellulose.
_______ Enzymes isolated from extremophiles have been very useful in laboratory research. For example, Taq polymerase facilitates PCR, a revolutionary technique for production of DNAs of particular sequences, which requires cycling reactions through high temperatures.
_______ Plants and animals require nitrogen to make biological macromolecules, however they’re unable to convert atmospheric nitrogen (N2) into a biologically useful form.
_______ Azithromycin is a drug that binds to 70S ribosomes and blocks synthesis of any new proteins.
_______ Methicillin-Resistant Staphylococcus aureus (MRSA) can cause life-threatening infections of the skin and bloodstream. One of the reasons MRSA infections are so serious is that they are resistant to treatment by many antibiotics, including methicillin and penicillin.
_______ The enzyme reverse transcriptase, isolated from retroviruses, is an important tool in molecular biology research. Scientists interested in learning what genes are turned on in particular cells use it to make DNA copies of RNAs they are studying (The DNA copies are useful because they are more stable).

When you have completed the matching activity, answer these follow-up questions:
• What types of infections can be treated with the following drugs?
o Penicillin
o Clotrimazole
o Azithromycin
o Tamiflu
o Raltegravir
• Why are these drugs (above) safe for you to take? That is, why don’t they kill your cells?
• Cancer cells are your own human cells that have become deregulated so that they divide and pile up in an uncontrolled way. Many chemotherapy drugs treat cancer by interfering with cell division and other cell processes.
o Why are there so many more side effects for individuals undergoing chemotherapy than for individuals taking antibiotics?

13. The arms of a human and the wing of a bat are _________________ structures, composed of the same bones that have been modified for different functions.

14. Xeroderma pigmentosum is an autosomal recessive genetic disorder. People who are homozygous for the disease-causing allele have skin that is damaged by exposure to ultraviolet radiation; this can lead to skin cancer at an early age. The mutation that causes this disorder is in a gene that functions:

15. The Amish are a religious sect descended from a small group of colonists who came to the United States over 200 years ago. Their religious beliefs have kept them isolated from society. The Amish have a much higher than average incidence of both polydactyly (extra fingers and toes) and dwarfism in their communities. This is most likely explained by:

16. In the structure of DNA that Watson and Crick proposed, the sides of the "ladder" of the DNA molecule are always the same distance apart, making the molecule a constant width. This occurs because when the bases hydrogen bond to form the rungs of the "ladder", a:

17. The RNA transcript of DNA that travels to the cytoplasm, carrying the instructions to make a protein, is called:

18. When DNA is replicated, the error rate is approximately one error for every 10,000 nucleotides copied. However, that error rate is reduced to only 1 error for every 1 billion nucleotides. The DNA sequence is "corrected" by:

19. Mendel's principle of segregation says that:

20. Tay-Sachs disease is lethal before reproductive age, but the allele persists in Louisiana French Canadians because:

21. Physical features that are similar in organisms which are not closely related to each other are most likely a result of ____________. A good example of this is the similarities seen between some marsupial and placental mammals.

22. In humans, which of the following sex chromosome compliments could be found in males?

23. The proteins that are associated with eukaryotic chromosomes:

24. A sequence of DNA nucleotides that contains the information to produce a single protein is a(n):