1. Today’s Date Here
Objective Here

2. Brainteaser
What's colorless and weightless, but if you put it into a barrel, the barrel would become lighter?

3. replication of organelles disappearance of the nucleolus
Meiosis and mitosis are two different reproductive processes. What happens ONLY during meiosis?
crossing over occurs
replication of organelles
disappearance of the nucleolus
complete breakdown of the nuclear membrane

4. Review DNA can be found in the nucleus
Ribosomes make proteins and are found in the cytoplasm
How does DNA (which doesn’t leave the nucleus) get to the ribosomes in the cytoplasm?
It becomes RNA and leaves through the nuclear pores.

5. DNARNA Proteins Traits
Central Dogma
DNARNA Proteins Traits
This is the central theme of molecular genetics.
This are the steps needed to get from a DNA double helix to your blue eyes.

6. Central Dogma How do you get from DNA to RNA to Proteins to Traits?
Amino Acids
DNA  RNA  PROTEINS  TRAITS
TRANSCRIPTION TRANSLATION control

7. Transcription DNA to RNA

8. DNA vs. RNA DNA RNA Deoxyribonucleic Acid Deoxyribose sugar
Double stranded
N bases = A,T,C,G
Found in the nucleus
1 type
Contains a phosphate, sugar, N base.
Ribonucleic Acid
Ribose sugar
Single stranded
N bases = A,U,C,G
Uracil replaces Thymine
Found in the nucleus and cytoplams
3 types
Contains a phosphate, sugar, N base.

9. DNA vs. RNA
DNA
RNA

10. Types of RNA Messenger RNA mRNA
Carries info from DNA and delivers it to ribosome.
Ribosomal RNA
rRNA
Structural component of ribosomes
Transfer RNA
tRNA
Translates mRNA sequences into amino acid sequences

11. TRANSCRIPTION The process that makes RNA from DNA in the nucleus
RNA Polymerase binds to a promoter region of DNA (sequence of DNA that signals the start of transcription)
Enzyme unwinds DNA and separates 2 strands. One strand of DNA acts as a template for making RNA

12. 3) Enzyme moves along bases of DNA in one direction
3) Enzyme moves along bases of DNA in one direction. It reads each nucleotide and pairs it with complementary RNA nucleotide.
4) Process continues until enzyme reaches a terminator (stop signal)
5) Enzyme detaches from DNA and releases RNA into nucleus

13. Transcription and Translation
12/25/2018
Transcription
RNA polymerase acts here
The enzyme RNA polymerase opens the DNA strands and synthesizes an RNA complementary to only one of the DNA strands.
G. Podgorski, Biol 1010

14. Transcription and Translation
12/25/2018
Transcription is a Key Step in Trait Expression
Transcription makes an RNA copy of DNA.
G. Podgorski, Biol 1010

15. DNA - RNA What would the mRNA strand be if the DNA template is:
(remember that A now pairs with U and C still pairs with G)
ATC CAG TCA GAT CTA CCG TGA CTG

16. How does the DNA become RNA?
Through a process called Transcription
Steps:
RNA Polymerase binds to a region of DNA that signals it to start making RNA.
RNA Polymerase unwinds the DNA and separates into 2 strands.
One strand of DNA acts as a template for making mRNA
Enzyme moves along the DNA bases in one direction. It reads each nucleotide and pairs it with a complementary RNA nucleotide.
Process continues until enzyme reaches a terminator (stop signal)
Enzyme detaches from DNA and releases mRNA from the nucleus.

17. PROTEINS

18. 2 Types: Structural = Build the body (skin, hair, muscle, blood)
Enzymes = speed up, slow down, start, or stop cellular/chemical reactions (usually end in –ase)

19. DNA → Proteins → Traits Controls the Expression of
Controls the Production of

20. TRAIT: HAIR COLOR VARIATION: THE DIFFERENT COLORS
Traits vs. Variations
Trait – a specific characteristic; eye color, or height that varies from one individual to another
Variation – the differences that an organism can inherit for a trait
TRAIT: HAIR COLOR VARIATION: THE DIFFERENT COLORS

21. Variations
Of a
Trait
Differences
Within a
Protein →
Results In

22. Examples:
Trait = Eye color
Variation 

23. Examples:
Trait = Hair Color
Variation 

24. Examples:
Trait = Skin Color
Variation 

25. Amino Acids
Proteins are made up of repeating units called amino acids. All amino acids have a similar basic structure.
There are about 20 different amino acids. A protein may contain anywhere from 50 to 5,000 amino acids. A different number and/or order of amino acids results in a different protein

26. DNA → Proteins → Traits Summary
Makes up amino acids which make proteins
DNA → Proteins → Traits
Controls the Production of
Controls the Expression of

27. Which function is characteristic of RNA, but NOT of DNA?
transports proteins
replicates itself
transports amino acids
carries genetic information