Bacterial Genetics (BE #5) Flashcards
Name the 3 parts of a nucleotide
- sugar
- phosphate group
- nitrogenous base
What is the building block of nucleic acid?
nucleotide
What does DNA stand for?
deoxyribose nucleic acid
In the ladder analogy of DNA structure, what kinds of molecules make up the sides of the ladder?
sugars & phosphates
What kinds of molecules make up the rungs of the ladder?
nitrogenous bases
What part of the nucleotide spells out the genetic message or code int he DNA molecule?
nitrogenous base
Name the 4 nitrogenous bases in DNA molecule.
- Adenine
- Thymine
- Guanine
- Cytosine
Describe complimentary base pairing (what pairs with what?).
A - T
G - C
Describe the prokaryotic chromosome.
single
circular chromosome
contains essential genes
Describe a plasmid.
circular
can be multiple plasmids
an extra chromosome that has nonessential genes
Why is a plasmid not considered another chromosome?
contains nonessential genes
Name 2 cellular processes that involve DNA (what does cell do with it?)
- replication
2. protein synthesis
What do genes code for
proteins
We say that DNA controls everything that is going on in the cell. How?
Through the production of enzymes, which are proteins. Enzymes catalyze chemical reactions, so help the DNA control cellular activities.
Briefly describe DNA replication.
an enzyme causes the hydrogen bonds between the 2 DNA strands to “unzips” & they separate. Each strand acts as a template directing the synthesis of a new complementary strand along its length. A-T, G - C
Why is DNA replication referred to as “semi conservative?”
This replication keeps half of the original strand & adds a new strand to it.
What would conservative replication look like?
Duplicating the DNA molecule with 2 completely new strands.
What are the 2 major events in protein synthesis?
Transcription
Translation
During the 2 major events in protein synthesis, what gets made in each event and what kinds of nucleic acids are involved in the event (DNA, mRNA, rRNA, and/or tRNA)?
Transcription - make mRNA, DNA & mRNA involved
Translation - make protein (assemble amino acids); mRNA, tRNA & rRNA are involved.
What does RNA stand for?
ribonucleic acid
How is transcription different in eukaryotes vs. prokaryotes?
B/c prokaryotes don’t have the noncoding sequences like eukaryotes, they don’t have to do the extra step of getting rid of them before the mRNA can be translated into protein.
What are the 3 types of RNA & what is the function of each in protein synthesis?
- mRNA - copy of the DNA molecule; contains the code for the amino acid sequence in the protein.
- tRNA - transfers amino acids to the ribosome to be assembled into the protein; very specific for the amino acid it transfers; has an anitcodon at one end.
- rRNA - reads the mRNA & directs the assembly of the protein.