Chapter 8-11

On mRNA, what is the Genetic Code?

3 nucleotide bases constitutes a codon, one codon = one amino acid, 64 codons (4) but only 20 amino acids used in making proteins, also 1 start and 3 stop codon

What is Chargaff's rule of base pairing?

A=T and C=G

What is the primary "energy currency" molecule of a living cell? What/where is the source of energy in this molecule? How is this energy released to drive chemical reactions?

ATP. The source of energy in this molecule is in the high energy phosphate bonds. When these bonds are hydrolyzed, they release energy to drive chemical reactions

If the base sequence of the DNA strand used as a template for messenger RNA synthesis is TACGTT, then what would be the sequence of bases in the corresponding mRNA?

AUGCAA

How are tRNAs connected with the correct amino acid?

Aminoacyl-tRNA synthesase

On a molecular level, what actually is a mutation?

Any change in the DNA nucleotide sequence of a gene

Describe the 3D structure of DNA. What type of forces or chemical bonds holds the two strands together?

Double helix, antiparallel, double stranded. Hydrogen Bonding

What organism developed the original genetic code used by all other life forms on Earth?

Bacteria

How is it possible that a single base change in a gene could result in a genetic disease? Give an example to support your argument.

Because once there is a mutation, all codons from that point are changed and the whole DNA strand becomes something completely different.

Explain how a genetic mutation for an enzyme involved in metabolism can cause disease.

Certain key enzymes are requires, without them can result in a build up of disease.

What is the difference between a codon and an anticodon?

Codon is found on mRNA, anticodon is found on tRNA

Where in a cell does protein synthesis occur?

Cytoplasm

In the Hershey-Chase experiment what was found to be the genetic material?

DNA

Structurally, what is the difference between DNA and RNA?

DNA is double stranded while RNA is single stranded

What is the difference between DNA and RNA?

DNA is genetic information, double stranded, deoxyribose, A,G,T,C while RNA is a copy of DNA, single stranded, ribose, A,G,U,C

What role do DNA ligase

DNA ligase joins the newly synthesized Okazaki fragments

Describe the structure of DNA. What is the building block of DNA?

Double helix, antiparallel, double stranded, base (ATCG) + sugar + phosphate= nucleotide

Discuss the flow of genetic information. In your answer be sure to explain in detail the process of transcription and translation.

First, the information in a DNA sequence is copied into a complimentary RNA sequence which is called transcription and then the RNA sequence is used to create the amino acid sequence of a polypeptide which is called translation.

In what direction does DNA replication progress?

Five prime to three prime

What are the two major types of genetic mutation? Which type is more likely to result in the expression of nonfunctional proteins, why.

Frameshift mutations and point mutations. The frameshift mutation is most likely to result in the expression of nonfunctional proteins because it changes all the amino acids of the sequence.

Before DNA polymerase can replicate DNA, the duplex must be opened up. What enzymes are responsible for unwinding DNA and stabilizing the single strands?

Helicase and single strain diamose

What landmark experiment was the first to confirm that DNA, not protein, is the genetic material?

Hershey-Chase Experiment

Describe in detail the translation process. What four steps are involved?

Initiation - the anticodon of first tRNA/amino acid aligns with start codon (AUG) on mRNA Ribosome complex formation - the ribosome forms around the mRNA Chain elongation - according to the codon sequence of the mRNA, tRNAs deliver the correct amino acids to a growing polypeptide chain Termination - stop codon on mRNA ends the process. A protein release factor binds to the stop codon and promotes the release of the last tRNA and the subsequent release of the newly formed protein from the ribosomal complex

Describe the process of transcription. What steps are involved?

Initiation binding of RNA polymerase to promoter site of gene, elongation which includes unwinding of DNA to expose the nucleotide bases on sense strand for pairing with complimentary RNA nucleotides and then joining RNA nucleotides with the RNA polymerase to form single strand RNA lastly the separation of the RNA strand from DNA followed by closure of DNA helix, then comes the termination where certain base sequences on DNA specify this termination spot.

What is the molecular basis for phenylketonuria?

It cannot properly process excessive amounts of phenylalanine, results in the build up of the toxic metabolite, phenylpyruvate

What must first be added to the template strand before DNA polymerase can lay down new DNA. What enzyme is responsible for this the addition?

It's able to replicate if there is short starter strand called a primer which is already bound. This primer must be added before DNA polymerase can lay down new DNA and the enzyme that is responsible for this addition is called primase

When and why is amniocentesis used?

It's usually performed from the fifteenth to the seventeenth week of pregnancy and it's usually performed to examine the genetic profile of the embryo or fetus to determine whether or not they are carriers of a disease

What is a replication fork? How does DNA replication on leading and lagging strands differ?

It's where the double helix is opened up by DNA helicase to expose the two DNA strands. Leading strands are orientated so that DNA synthesis progresses in a 5' to 3' direction. Lagging strands occur discontinuously because the DNA is exposed in a 5' to 3' direction therefore a short RNA primer is synthesized and then it's extended on a 5' to 3' direction with short 3' fragments which are called Okazaki fragments

Do "inborn errors in metabolism" always result in death? Give an example.

No. An example is albinism where the person cannot make melanin

Where on the DNA strand does DNA replication begin?

On the origin of replication

What is translation?

RNA to protein

How is DNA replication different from transcription?

The genetic information in DNA is copied to RNA, In transcription, the end result is a single strand of genetic information

The linear sequence of amino acids in a protein is determined by what?

The linear sequence of nucleotides in DNA/RNA

What is the Central Dogma of genetic information?

The process where the gene changes to RNA and then to protein then to cytoplasm

How do defective proteins lead to diseases?

The proteins become dysfunctional and can no longer do what their intended for

How is DNA replicated? List its three steps.

Unwinding, complimentary base pairing, and joining

Genetic expression. In an illustration of a cell, be able to label where you would find DNA, RNA, protein and the processes (transcription, translation) involved in going from a gene to a protein.

got it

What role do the three types of RNA produced during transcription play during translation?

mRNA is the messenger which has the genetic information copied from DNA and knows what protein to make and how. Next is the tRNA and this transfers RNA and carries amino acids to mRNA for making protein. Lastly is the rRNA, the ribosomal RNA which is a key component of ribosomes serve as scaffolding, ribosomes have catalytic activity