DNA
living ________
things
•Proteins are found in all ________
•Are species specific/ individual specific (transplant rejections)
Importance of DNA
•Chromosome: DNA + ____
RNA
nucleotide 5 carbon sugar , nitrogen base and phosphate
•__________:
Cut and paste a nucleotide here
•1953 Watson and Crick – model of DNA molecule
as a spiral helix
•Double helix (like a ladder twisted on its long axis)
•Side of ladder – sugar and phosphate
nitrogen ______
base pairs (draw here)
•Rungs = _________
four nitrogen bases in DNA:
•Only _____
•Purines:
•Pyrimidines:
adenine and guanine
thymine and cytosine
•Arranged in complementary base pairs:
•A------T
•G------C
All Teachers
Go Crazy
Replication of DNA
•Replication = ________________________________________________
the process of making an identical copy of a section of
double stranded DNA
________________________________________________
•DNA ladder unzips at base pairs
•Free nitrogen bases assemble on the open strands,
forming two new complete strands.
•Occurs with a great degree of accuracy
•Requires enzymes called DNA polymerases
Transcription: copies the information of DNA
DNA segment
•Transcription = making complementary copy of _________
Is it an exact copy? Explain why or why not?
•Made inside the nucleus
•Leaves nucleus and goes to ribosome in cytoplasm to direct synthesis of protein
•RNA differs from DNA. RNA has:
•One strand
•Ribose sugar
thymine as fourth nitrogen base
•Uracil replaces __________
•RNA is smaller than DNA
•Three types of RNA
ribosome
•1: mRNA – carries “recipe” from protein to ____________
•2: tRNA – carries amino acids to ribosomes
•3: rRNA – in ribosome
•mRNA transcribes in nucleus:
•mRNA leaves nucleus and moves to ribosome to direct protein synthesis
•Codons determine amino acid sequence
mRNA that codes for an amino
•Codon = group of three nitrogen bases on ________
acid. Also called triplets.
•2-3 codons for each amino acid (20 -22).
AUG
•1 codon (_______)
is start codon.
•Several stop codons.
PROTEIN SYNTHESIS
•Translation: proteins are synthesized
ribosome
•mRNA moves to _____________.
•Acts as a template for protein synthesis.
•tRNA has anticodon that will match mRNA codons.
•As ribosomes move across mRNA, tRNA brings appropriate amino acids to it.
Amino acids bond together forming a peptide chain, which forms a
•__________
protein
polypeptide, which, when reaching macromolecular size, is a ______________.