2 - Genes Flashcards
- Purines=
- Pyrimidines=
- Phosphodiester bond=
- Purines= adenine and guanine; which are two-ringed structures.
- Pyrimidines= cytosine and thymine; which are single-ringed structures.
- Phosphodiester bond= each nucleotide is bound by a phosphodiester bond between the third carbon of one deoxyribose and the fifth carbon of the other creating the sugar phosphate backbone of a single strand of DNA.
- hydrogen bonds keep the two strands of DNA together.
- A bonds with T (2 bonds)
- G bonds with C (3 bonds)
- DNA replication–>
- replication is
- DNA polymerase is the enzyme which carries out
- Okazaki fragments=
- DNA ligase=
- the leading and lagging strand replication process is called
- Telomeres= .
- DNA replication–> semi-conservative
- replication is bi-directional; two directions at once.
- DNA polymerase is the enzyme which carries out replication, but it needs an RNA primer to begin work (reading in the 5—>3 direction).
- Okazaki fragments= 100-200 in euk and 1000-2000 in prok.
- DNA ligase= the enzyme which connects okazaki fragments together.
- the leading and lagging strand replication process is called semidiscontinuous.
- Telomeres= repeated 6 nucleotide units from 100-1000 units long to protect chromosomes during replication.
Replication’s five steps:
1)
2)
3)
4)
5)
Replication’s five steps:
1) helicase unzips the double helix
2) RNA polymerase builds a primer
3) DNA polymerase assembles the leading and lagging strands
4) the primers are removed
5) Okazaki fragments are joined
- rRNA=
- tRNA=
DNA is only in the ______ and in the ______, while RNA can also be in the _____.
- rRNA= combines with proteins to form ribosomes.
- tRNA= collects amino acids in the cytosol, and transfers them to the ribosomes for incorporation into a protein.
DNA is only in the nucleus and in the mitochondrial matrix, while RNA can also be in the cytosol.
Transciption:
1)
2)
3)
4)
- Transcription is about_____ slower than ______
- only the template strand of the DNA is transcribed which is seen as the _______ and resembles the ______ sequence of RNA.
Transciption:
1) initiation is the first step
2) Promoter is a spot of DNA which tells the RNA poly where to begin
3) elongation
4) termination; requires a termination sequence and special proteins to dissociate RNA poly from DNA
- Transcription is about ten times slower than DNA replication.
- only the template strand of the DNA is transcribed which is seen as the coding strand and resembles the universal code sequence of RNA.
- Activators or Repressors=
- Operon=
5’ cap=
Poly A tail=
- Activators or Repressors= regulation of gene expression occurs at the level of transcription via proteins.
- Operon= genetic unit usually consisting of the operator, promoter, and genes that contribute to a single prok mRNA.
5’ cap= serves as an attachment site in protein synthesis and as a protection against degradation by exonucleases.
Poly A tail= also to protect it from exonucleases.
-introns remain in the nucleus, but exons exit the nucleus to be translated, and most typically snRNPs in the nucleus remove introns within the gene.
- Restriction Enzymes=
- Palindromic=
- Recombinant DNA=
- Restriction Enzymes= digest or cut nucleic acid only at certain nucleotide sequences along the chain.
- Palindromic= a sequence that is read the same backwards and forwards.
- Recombinant DNA= two DNA fragments cleaved by the same endonuclease and rejoined together.
How to make a DNA library:
1)
2)
3)
How to make a DNA library:
1) take your DNA fragment and insert into a bacterial vector
2) lets the bacterium reproduce like crazy
3) Your DNA has now been cloned along with your DNA fragment.
- Probe=
- Complementary DNA (cDNA)=
- PCR=
- Southern blotting=
- Northern blotting=
- Western blotting=
- Probe= radioactively labeled complementary sequence of the desired DNA fragment which is used to search the library.
- Complementary DNA (cDNA)= when mRNA is reverse transcribed using reverse transcriptase. (lacks introns!!!)
- PCR= a much faster way of “cloning.”
- Southern blotting= a way to identify target fragments of known DNA sequence in a large population of DNA.
- Northern blotting= does the same thing as southern blotting but does it for RNA.
- Western blotting= detects a protein with antibodies.
Steps for N or S blotting:
1)
2)
3)
4)
5)
-Electrophoresis uses a_______ anode, and a __________ cathode.
Steps for N or S blotting:
1) chop up DNA
2) Use electric field to spread out pieces according to size
3) blot it out onto a membrane
4) add radioactive probe made from DNA or RNA
5) visualize with radiographic film
-Electrophoresis uses a positively charged anode, and a negatively charged cathode.
-Degenerative=
Start codon:
Stop codon:
-Degenerative= more than one series of three nucleotides may code for any amino acid.
Start codon: AUG
Stop codon: UAA, UGA, UAG
mutations web:
- Histone=
- Nucleosome=
- Chromatin=
- Histone= DNA not in use are wrapped tightly around globular proteins.
- Nucleosome= eight histone wrapped in DNA form this.
- Chromatin= the entire DNA/protein complex.
CELL LIFE CYCLE:
four stages:
1)
2)
3)
4)
interphase=
CELL LIFE CYCLE:
four stages:
1) first growth phase (G1)
2) synthesis (S)–> chromosome duplication
3) second growth phase (G2)—> prepare to divide, cellular organelles continue to replicate
4) mitosis or meiosis (M)/ cytokinesis ©
interphase= G1,S, and G2
Mitosis= )
Meiosis=
Mitosis= nuclear division without genetic change. (PMAT)
Meiosis= double nuclear division which produces four haploid gametes (germ cells). Only sperm cells and oogonium undergo meiosis.
-after S phase of interphase—> they are primary speratocyte/oocyte
Meiosis web
