-
What did Hershey and Chase observe and
conclude? (know what a bacteriophage is, and understand the experiment)
- Hershey and Chase took bacteria
- (e. coli) and bacteria attacking viruses (backteriopahe T2) to find if protein
- or DNA contained genes. (Side by side
- radioactivity experiments)
-
What macromolecule transfers information
from one generation to the next?
- DNA & RNA are long linear
- polymers, called nucleic acids that transfer information from one generation to
- the next
-
What are the 3 basic components of DNA and RNA, and how are they
arrayed?
- 5 Carbon sugar, phosphate
- group, and a nitrogen base
-
What are the 4 nitrogenous bases used in
DNA? In RNA?
- DNA-Adenine (A), Cytosine (C),
- Guanine (G), Thymine (T)
- RNA-Adenine (A), Cytosine (C),
- Guanine (G), Uracil (U)
-
Who discovered the molecular structure
of DNA?
Watson and Crick
-
What is base complementarily (base
pairing), and why is it important?
- Base
- paring=nucleotides from pairs through hydrogen bonding, to create a double
- helix (e.g A-T, C-G). Base pairing
- allowed a mechanism for replication and explained structure
-
How do the two strands of DNA line up
(their relative directionality)?
-
What is the directionality of a strand of DNA based on?
- Directionality
- of sugar-phosphate backbone carbons are numbered on the sugar (pentose
-
How is DNA replicated? Include
information about the replication bubble, DNA polymerase, and DNA ligase.
- DNA
- Polymerase: copies each strand, is direction specific.
- Replication
- bubble: enlarges on each end at the replication fork
- DNA ligase:
- fills the final gaps in the sugar phosphate group
-
The plans in DNA are used to make
proteins in two steps. What are they?
- Transcription
- RNA synthesis based on a DNA template in nucleus
- Translation-
- protein synthesis from RNA template in cytoplasm
-
What is transcription, and where does it
take place?
- Protein
- synthesis from RNA template, takes place in Cytoplasm
-
Show how mRNA is transcribed from a DNA
strand, including RNA polymerase, promoter
sequences, and termination sequences
- enzyme RNA
- polymerase uses the genes from DNA template strand to make mRNA, adding
- nucleotides in the 5’ -> 33 direction
- 1.
- initiation:RNA
- pol starts transcriptions at a promoter sequence on the DNA template strand
- 2.
- elongation:
- RNA pol elongates mRNA by adding nucleotides in on the 3’ end of the growing
- strand
- 3.
- termination:
- when RNA pol reaches a termination sequence at the end of the gene, the mRNA
- pol detach and float away separately
-
What is the difference between an intron
and an exon?
- Introns: parts
- of mRNA that are not used for making the protein (non-coding)
- Exons: parts
- of mRNA that are necessary for making proteins (coding)
-
What is translation, and where does it occur?
Using code in processed mRNA to make a protein-occurs in cytoplasm
-
What is meant by redundancy of the genetic code?
Redundancy: more than one codon fro many amino acids
-
How does tRNA link the codon on mRNA with an amino acid?
tRNA: 64 varieties, each one has a particular anticodon couples with a particular amino acids which it binds with
-
Show how mRNA is translated (rRNA, tRNA, anticodon, ribosome).
- mRNA-transcribed from DNA: contains plans to be translated tRNA-64 varieties: each one has a particular amino acid that it binds to Ribosomes: organelles with two subunits: large and small
- -composed of rRNA and proteins
- -large subunit link to tRNA
- -small subunit link to mRNA
-
How does translation start and stop? Be able to translate if provided the codon chart.
Translation starts with the ‘start’ codon AUG, and ends at any of the ‘stop’ codons
-
What do the two subunits of the ribosome
do?
-
How do different types of mutations affect the organismal phenotype?
- Base Mutations:
- one base is replaced by another; may or may not change amino acid, may or may
- not change protein function
- Deletion: one
- or more nucleotides is deleted; may change amino acid sequence from that point
- forward unless a multiple of three
- Insertion: one
- or more nucleotides is added; may change amino acids sequence from that point
- forward unless a multiple of three
-
What are viruses, viroids, and prions?
- Viruses: DNA
- (ex. Chicken pox) or RNA (ex. AIDS, colds) in a protein coat which puncture the
- cell membrane and insert genetic material to reproduce
- Viroids: small
- RNA molecules that infect plants- NO PROTEEIN PRODUCTION
- Proins:
- proteins currently thought to be misfolded; misfolding id=s contagious
-
What is the difference between the lytic cycle and the lysogenic cycle in bacteria?
-
Potential exam question: What two things happen to mRNA before it passes out of the nucleus, and why
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