Download presentation
Presentation is loading. Please wait.
Published byLillian Griffith Modified over 11 years ago
1
DNA Deoxyribonucleic Acid “The Blueprint of Life”
I. DNA Structure & Function
2
A. What is DNA? 1. Organic molecule 2. Nucleic acid
3
B.Where is it located? 1. Nucleus 2. Chromosomes X DNA
4
Chromosomes in Nucleus
5
C. Structure of DNA Nucleotides a. Phosphoric Acid
b. Deoxyribose sugar c. Nitrogenous bases: Adenine-Thymine Guanine-Cytosine 2. Ladder Shape 3. Double strand, helix twist
6
Ladder Shape (Sides & Rungs)
Sugar Acid Sides: Phosphoric Acid Sugar Rungs: A-T T-A G-C C-G T-A G-C C-G A-T
7
Watson & Crick’s Double helix:
8
D. What is DNA’s Function?
Hereditary Instructions Chemical code for every trait “Blueprint” for making Proteins
9
Genes = Segments of DNA Code for a trait Chromosome DNA Code: Eye
Hair Color Genes = Segments of DNA Code for a trait X Eye Color
10
DNA Chromosome Code: Sets of 3 Nucleotides Code for Trait Triplets= X
Acid Acid Sugar-T-A-Sugar Acid Acid Sugar-G-C-Sugar Sugar-C-G-Sugar X
11
*** *- ** *-* DNA Chromosome Code: A-T G-C C-G T-A
*** *- ** *-* Like Morse Code: Hair = Or DNA A-T G-C C-G T-A
12
DNA Replication Chromosomes double Mitosis Late Interphase 2n to 4n 2N
13
E. Steps for DNA Replication:
DNA untwists DNA unzips Corresponding base pairs Line up In sets of 3 nucleotides (triplets) Or “codons” DNA reforms 2 strands twist into helix Identical Strand
14
RNA Ribonucleic Acid “DNA messenger & taxi”
II. RNA Structure & Function
15
A. What is RNA? Organic Molecule Nucleic Acid mRNA= Ribonucleic Acid
messenger tRNA= transfer Ribonucleic Acid
16
mRNA in nucleus & cytoplasm
B. Where is RNA located? mRNA in nucleus & cytoplasm tRNA only in cytoplasm mRNA mRNA tRNA
17
B. What is RNA’s structure?
Nucleotides= a. Phosphoric Acid b. Ribose sugar c. Nitrogenous Bases: Adenine-Uracil Guanine-Cytocine 2. Single Strand 3. No Twisted helix Acid Sugar-Base
18
Comparison of RNA & DNA:
Acid Sugar-Base Acid Acid Sugar-Base-Sugar Acid Acid Uracil Thymine Deoxy-ribose Ribose RNA DNA Ladder
19
D. What are RNA’s functions:
mRNA= Copies the DNA code Deliveries message to Ribosome Protein Factories
20
Why not send the original DNA code out?
DNA might be damaged! mRNA components are reused To copy more messages mRNA copy
21
RNA function cont. tRNA in cytoplasm Picks up an amino acid
“Taxis” the aa to the Ribosome protein factories Amino acid tRNA
22
Assembling Proteins from the DNA Instructions
III. Protein Synthesis Assembling Proteins from the DNA Instructions
23
A. Transcription: mRNA is copied off of DNA In nucleus Steps:
DNA untwists DNA unzips RNA codons line up
24
Transcription: mRNA DNA Code A T C G U A G C I I I mRNA has:
Ribose sugar Uracil instead of thymine bases Nuclear membrane allows it to leave! mRNA A T C G U A G C I I I DNA Code
25
Transcription in The nucleus DNA mRNA copy
26
B. Translation = Conversion of the message (mRNA Code) Into a protein
By the ribosome factories
27
B.Translation A U A G C U mRNA code C mRNA arrives at the Ribosome
tRNA taxi A mRNA arrives at the Ribosome tRNA picks up an amino acid tRNA delivers the aa to the ribosome aa are assembled into polypeptide proteins U C G U A G C mRNA code
28
2. Peptide bond forms tRNA delivers 3. tRNA leaves ribosome amino acid
4. Polypeptide Chain of amino acids grows 2. Peptide bond forms 3. tRNA leaves ribosome tRNA delivers amino acid
29
Summary: Protein Synthesis: Transcrition: Make mRNA From DNA
Translation: Make protein Off mRNA code Using amino acids DNA Replication: Make duplicate DNA In nucleus Copy the chromosomes For Mitosis
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.