Protein Synthesis Review

DNA and RNA

100

DNA is found in.....

the nucleus 

200

In DNA, the base pairing rules are....

In RNA, the base pairing rules are...

A to T, C to G 

A to U, C to G

300

List the 3 differences between DNA and RNA 

RNA is single stranded, DNA is double stranded

RNA has base uracil instead of thymine in DNA 

RNA has the sugar ribose, DNA has the sugar deoxyribose

400

List and describe the 3 types of RNA

mRNA: messenger RNA that is the copy of a gene from the DNA 

tRNA: transfer RNAs that bring amino acids to the ribosome during translation

rRNA: ribosomal RNA makes up the ribosome

500

In a sentence, relate DNA and RNA to each other. Be sure to use the follwoing terms: base-pairing rules, complementary, and sequence

RNA is a copy of a sequence of DNA that is comprised of the complementary nucleotides based on base pairing rules. 

Transcription

100

Location of transcription

the nucleus

200

Cells of different types will make _________ proteins

Explain your answer 

Different proteins because different genes are transcribed based on the job of the cell type (intestinal cells will make different proteins than a brain cell)  

300

The enzymes needed for transcription to occur and what they do in the process 

Helicase: unzips DNA double helix, exposing the sequence to be copied 

RNA polymerase: builds complementary mRNA molecule from the now exposed DNA sequence, makes the mRNA polymer 

400

Transcription can be regulated through genetic sequences known as

operons 

500

***DAILY DOUBLE***

You decide to dump a glass of chocolate milk on a culture of bacteria, describe how the bacterial cultural digests the lactose in the milk starting from transcription and ending with the digestion of lactose. 

Bacteria absorbs milk, cells are exposed to lactose, lactose binds to repressor protein on operator region of gene and forces it off, allowing cells to transcribe gene for lactase, many mRNA transcripts are made and sent to ribosomes. Ribosomes begin synthesis of lactase based on mRNA codes provided. Lactase is now made and begins digestion of lactose that has been taken in by cells in the cytoplasm. Lactase will eventually digest the lactose bound to the repressor protein, which will allow the repressor to bind to the operator again and block any further transcription of the gene

Translation

100

Location of translation 

in the cytoplasm at a ribosome 

200

Transcribe and translate this DNA sequence:

TAC CCA GGA GCT TTG ACA GGG

Transcription: AUG GGU CCU CGA AAC UGU CCC

Translation:   Met—Gly—Pro—Arg—Asn—Cys—Pro

300

Give a potential DNA sequence for the following amino acid sequence

Met-Pro-Asp-Leu-Arg-Pro-Leu-Ser

Check answers

1 possible : TAC GGT CTA GAA TCT GGG GAG TCA (template strand)

 

400

Describe of tRNAs movement (after initiation) through the ribosome and how amino acids are added to the growing protein (Be specific)

tRNAs will enter the ribosome through the A site, their amino acid will be joined to the growing polypeptide in the P site, and the now empty tRNAs will leave throuhg the E site. This continues until termination

500

Describe initiation, elongation, and termination

Initiation: small ribosomal subunit recognizes start codon in mRNA and they bind together, tRNA holding Met will bind to top of mRNA strand and large ribosomal subunit will associate with the small, making the whole ribosome

Elongation: tRNAs enter through the A site, their amino acid is joined to the polypeptide at the P site, and the now empty tRNA leaves through the E site. This process continues until a stop codon is encountered.
Termination: once a stop codon enters the A site of the ribosome, a release factor will come in and bind in the A site, causing the ribosomal subunits to dissociate from each other, releasing the mRNA, the newly made protein, and any tRNAs remaining in the ribosome

Mutations

100

A mutation is...

a change in the DNA code

200

List the types of mutations

Point, insertion, deletion 

300

What kinds of mutation occurred in this protein? The normal and mutated amino acid sequences are shown below: 

Met-Glu-Gly-Asp-Leu-Arg-Trp-Ser

Met-Glu-Glu-Asp-Leu-Arg-Trp-Ser

missense: 3rd a.a. changed from Gly to Glu

400

***DAILY DOUBLE****

List the effects of mutations and describe each

Silent, missense, nonsense, frameshift

500

Which mutation is the most dangerous to individuals and why?

Frameshifts because the entire reading frame after the insertion or deletion is altered, changing many amino acids in the sequence as a result

Nonsense mutations are also bad but not as bad because it simply results in a shorter protein, while frameshift mutations can lead to shorter or longer, nonsensical proteins that can be deleterious to the human condition.

Misc.

100

What are prions and what can they cause?

Prions are misfolded proteins that can cause other proteins of their type to misfold, leading to neurological conditions and disorders 

200

What is an operon, what does it do, and what types are there?

An operon is a region of DNA before a gene that regulates its expression, they can be repressible (you can turn the gene off) or inducible (you can turn the gene on)

300

What is sickle cell anemia and what is it caused by?

Sickle cell anemia is a blood disorder where your RBCs have shorter lifespans and the hemoglobin found within them is misshapen, leading to sickle shaped RBCs that tend to clot and clump in blood vessels.

400

What is the function of myostatin and what will happen in cows if a mutation occurs within the gene that codes for it.

Myostatin is a protein that regulates and controls muscle growth in the skeletal muscle of mammals. If a mutation occurs within this gene, the protein will likely become faulty and muscle growth will be unregulated, leading to an increase in muscle mass

500

Give 2 examples of prion caused diseases and describe them in detail

Any of the following: 

Creutzfeldt-Jakob Disease (CJD)

Fatal Familial Insomnia

Bovine Spongiform Encephalopathy (BSE)

Chronic Wasting Disease (CWD)

Scrapie 

Kuru