dna to eye color? just how does it happen? problem? how do we go from dna to individual traits?
TRANSCRIPT
DNA to Eye Color?Just How does it Happen?
Problem?How do we go from DNA
to individual traits?
DNA acts as a blueprint
• DNA acts as a blueprint for making proteins
• It is these proteins that give you your hair and eye color!
Gee- what do ribosomes do?• Make Proteins• Where are they?• Cytoplasm & RER• DNA- the “recipe” for
making proteins is located in the nucleus
• HOW DO WE GET FROM NUCLEUS TO CYTOPLASM?
DNA to RNA?
• The instructions for assembling proteins are “transferred” from DNA to RNA, which is the second type of nucleic acid.
DNA vs. RNA
• Single Chain of nucleotides
• Sugar is Ribose
• Uracil instead of thymine
–Complimentary to adenine
Transcription• Transferring
information from DNA to RNA is called transcription
• Same as replication, except Adenine will pair with Uracil
–Fill in the strand
RNA Does the GRUNT WORK!• After Transcription-
RNA goes to the cytoplasm to find a Ribosome to make proteins
• 3 types of RNA to do this work!!
• mRNA• tRNA• rRNA
THE RNA’s • mRNA (messenger)
– Carries transcribed DNA code to ribosome
• tRNA (transfer)– Brings amino acids to
ribosome in correct order
• rRNA– w/ other proteins
makes up structure of ribosome
CHECKPOINT- Fill it in!!!!
• Double Helix
• Adenine
• Guanine
• Cytosine
• Thymine
• Deoxyribose
• Single Strand
• Adenine
• Guanine
• Cytosine
• Uracil
• Ribose
DNA RNA
CHECKPOINT 2
• mRNA
• tRNA
• rRNA
• Carries transcribed DNA code to ribosome
• Brings amino acids to the Ribosome
• Assists in ribosome structure
FINALLY! RNA to Proteins
First, ya gotta understand how the genetic code works!
Humans vs. Hard Drives
• DNA stores info in the form of long sequences of bases
• 30,000 genes in humans–3 billion base pairs
• Base pairs make up code for amino acid sequence, which make up the protein.
•A 3 base code in DNA or mRNA is called a codon.
Each codon translates to a particular amino acid.
•20 amino acids make up all proteins for life•Since codons are 3 bases, there are 64 different codon sequences
-Some amino acids have two or more codons.
These Codons are used by all living things; thus, showing the unity of life on
Earth
Protein Synthesis
• 1) Transcription- DNA is transcribed into mRNA in the nucleus
• 2) mRNA moves into the cytoplasm and attaches to a ribosome
Protein Synthesis (continued)• 3) Translation- the
ribosome reads the codon and matches it with its anticodon carried by the tRNA’s in the cytoplasm. Attached to these anticodons are the amino acids that will be built into a protein
Protein Synthesis (continued)• 4) Elongation-
Ribosome will continue to build proteins one amino acid at a time. During this time, tRNAs continue to bring the corresponding amino acids until ribosome enters a “STOP” codon.
– Ribosome falls off mRNA and protein ready for use
Now…Let’s practice