Nucleic acids
-the macromolecule that holds our genetic material (DNA)
-Contain Genes= sections of DNA that serve as the blueprint/instructions for making proteins
-located at certain points on a chromosome
-proteins carry out all cellular activity
Nucleotides
-Make up nucleic acids (the monomer)
-Have three parts:
Sugar
-DNA
-RNA
Phosphate
Nitrogen Base
-Adenine
-Guanine
-Cytosine
-Thymine
-Uracil
DNA structure
Double Helix: like a twisted ladder
-Sugar and phosphate form the “sugar phosphate backbone”
-Nitrogen bases bond in the middle with weak hydrogen bonds
-All other bonds are strong covalent bonds
Chromosomes
Tightly coiled strands of DNA
Gene
A section of DNA that has instructions to code for a protein
Chromosome
Collection of your DNA
Gene is your
Characteristics
allele is the
Variation/kind/type of characteristic
Where can a DNA molecule be found in a prokaryotic cell
Cytoplasm
Where can a DNA molecule be found in a eukaryotic cell
nucleus
What is a polypeptide
A chain of amino acids; can bind to others and fold into a protein
mRNA (messenger)
copies instructions in DNA and carries these to the ribosomes in the cytoplasm
tRNA (transfer)
binds and carries specific amino acids to the ribosomes
rRNA (Ribosomal)
Along with proteins, make up the ribosomes
Transcription DNA–> mRNA
Carries the code/instructions out of the nucleus
Process:
Unzip the gene that needs to be copied
Use complementary base-pairing rules to match RNA nucleotides with the exposed DNA nucleotides
Release the completed mRNA molecule
DNA zips back up and the mRNA leaves the nucleus and enters the cytoplasm
Genetic code
instructions for how to make proteins
codon
a set of 3 nucleotides on the mRNA
Anticodon
“complementary” 3 nucleotides on tRNA
Amino acid
Monomer building block for proteins, held together by peptide bonds
Translation mRNA–> Polypeptide
Read/follow the instructions carried on the mRNA to make a polypeptide
happens in the ribosomes
process:
mRNA attaches to a ribosome
Ribosome reads the mRNA codons, starting at AUG.
-1 codon=3 RNA nucleotides
tRNAs act like taxis to pick up and drop off the amino acids that match with each codon
tRNAs continue to drop off a.a. and the ribosome binds the amino acids together with polypeptide bonds ‘when the stop codon is reached, the ribosome releases the completed polypeptide chain
Translation
interpreting the RNA message into a polypeptide to make a protein
transcription factors
regulatory proteins that control gene activity
Epigenetics
the study of changes in gene expression that are heritable
-different from mutations
