Chapter 8 Flashcards
Importance of genetics
Understand cell function Evolution of species Advancement in agriculture Understand diseases Info on antibiotic resistance
What is genetics
Study of function and transfer of genes
What is genome?
ALL genetic info in cell
Contain chromosomes
How many chromosomes E.coli have?
How many genes?
How long is stretched out?
1 chromosome
4288 genes
Stretch 1mm if unwound
How many chromosomes do humans have?
Stretches??
46 chromosome
6 feet
What are chromosomes?
Contain genes
What are genes?
DNA segments
What are three types of genes?
Structural: code for protein
Regulatory: control gene expression
Genes that code for RNA
*structural most important
What are genetic code
Set of rules that determine how nucleotides sequence is converted into a protein
What is genotype?
Genetic make up
Represents potential characteristics
Ex. Serratia marcescens COULD turn red
Phenotype
Expression of genotypes
Actual observable characteristics
Ex. Serratia marcescens is red
What does DNA stand for
Deoxyribo Nucleic Acid
What are the component of Nucleic acid?
Nucleotides
What are the three nucleotides component?
5 carbon sugar
Phosphate
Nitrogenous base
What are the nitrogenous bases?
Adenine
Thymine
Cytosine
Guanine
What is complementary base pairing
Certain nucleotides bases pair together
A-T
G-C
What kind of bonds are between bases?
Hydrogen bonds
Each DNA molecule has
2 strands of nucleotides
Strained in DNA molecule are
Antiparallel 5’ –> 3’ and 3’ –> 5’
Carbon of dexoxyribose are numbered
1’ through 5’
5’ end _______ add nucleotides(P)
Cannot
3’ end _______ add nucleotides (OH)
Can
Flow of genetic information
DNA ————–> mRNA –> protein
^(Transcription). ^translation
DNA ————–> mRNA –> protein
^(Transcription). ^translation
Is called
Central dogma
what is genotype?
genetic make up
represent only potential charactersistics
ex. Serratia macescen COULD turn red
what are the steps of DNA replication?
- double helix is seperated by helicase
- replication fork forms at origin of replication
- leading strand is synthesized continously as DNA polymerase add new nucleotides (5’ to 3’)
- Lagging strand uses RNA primer to lay down short pieces of RNA
- On lagging strand, DNA polymerase removed RNA primer and replaces it with DNA
- On lagging strand DNA ligase joins fragments of DNA
- DNA polymerase proofreads to ensure proper base pairing occurs
how is the lagging strand formed?
synthesized in pieces because there is no free 3’ end
helicase
enzyme that unwinds double helix
template
original strand of DNA
where 2 strands are seperated and new nucleotides are added
replication fork
enzymes that add new nucleotides and proof reads
DNA polymerase
Small pieces of RNA where DNA polymerase can attach
RNA primer
enzyme that joins fragment of DNA (glue) on lagging strand
DNA ligase
Pieces of RNA fromed on teh lagging stand
OKAZAKI fragment
transcription
process of making mRNA from a DNA template
what is the end result of transcription?
mRNA
what does mRNA do:
carries infromation transcribed from DNA
contains codons
what does tRNA do?
carries amino acids
contains anticodons which pair with codons on mRNA