Bi 221 Week 10: Topic 14

RNA is ______ stranded

and

DNA is _____ stranded

single

double

What does RNA use to fold on itself?

H-Bonds

What is the base unit switch in RNA compared to DNA?

DNA A=T, while RNA A=U

RNA is cool as A Unicorn not A Tiger.

What does RNA have on it’s 2’ C?

-OH

Transcription-

making mRNA from DNA template

DNA directed synthesis of mRNA

Translation

making a protein from the info in mRNA

nucleotides → amino acids

In Eukaryotes, transcription happens in the ______ while translation happens in the ______

nucleus

cytoplasm

The white house scripted the speech in the oval office, and then the president translated it on the lawn

In Prokaryotes, transcription and translation ….

happen in the same place.

Codons -

3 nucleotides that code for one specific amino acid.

How many codons are possible?

How many amino acids are there?

64 possible codons

20 amino acids

What are codons considered?

Redundant - most amino acids are encoded by multiple codons

What is the start codon?

AUG (met)

We went to the met gala in AUGust

What is always the first codon in all genes?

AUG (Met) start codon.

What are the stop codons?

UAA

UAG

UGA

are stop codons included in the transcripted sequence?

No, it only includes the start codon up to the last codon before the stop

Codons are considered ______ because _______

Universal, all living organisms use the same gene code

Silent mutations allow for what?

Allow for change without changing the protein made.

LUCA

Last Universal Common Ancestor

small bacteria we all evolved from

UTR -

untranslated region has a 5’ and 3’

Gene

segment of DNA containing hereditary information

What are the 2 types of genes?

Protein coding

and

Non-protein coding

Protein coding genes

mRNA → proteins

H

How many types of protein coding genes are there?

20 thousand

Non-protein coding genes

make RNA ONLY

tRNA, rRNA, snRNA

What do non-protein coding genes lack that makes them hard to find?

They don’t have codons

Items found in a gene:

1. Transcribed region includes the

UTRs - 5’ and 3’

Translational units - Exons and Introns

Translational Units include

Exons and Introns

Items found in a gene:

2 Promoter

RNA pol bind and synthesized the RNA molecule

Items found in a gene:

Control elements

Proximal/distal

upstream 5’ / downstream 3’

enhancers / repressors

Transcription factors

proteins that bind the control element and promoter

required for the regulation of gene activity.

What are the steps of transcription?

Pre-mRNA → mature mRNA → protein synthesis

Exons

remain in mature mRNA

Contain protein coding region

Introns

removed from pre-mRNA strand

non-coding (no codons)

What happens to UTRs during RNA processing?

Added to the 5’ and 3’ end of the coding segment for protection

They aren’t removed or translated.

The template DNA strand is read….

3’ to 5’

mRNA is synthesized …..

5’ to 3’

snRNPs are made of

snRNA and proteins

What is the function of a snRNP?

Cut out introns and fuse together the exons

How many types of snRNPs are there?

4

What type of protein are snRNPs considered?

Catalytic as they cut introns OUT breaking bond

Catalytic bonds are like a cat breaking a glass by knocking it off a table.

Riboenzyme

enzyme made of RNA

How many genes do humans have?

How many proteins?

about 20 thousand genes

about 100 thousand proteins

To get a number of base pairs, or nucleotides, you need to multiply your amino acid by ____.

3

What is the range of exons and introns in each gene?

10-100

What does the different combination of exons lead to?

Different proteins

Alternative Splicing is only for what type of cell?

Why?

Eukaryotes

Because the transcription and translation are separated.

What is tRNA (transfer RNA) made of?

45 genes/types of tRNA

Anticodon on top, amino acid binding site on top.

tRNA’s anticodon always attaches to the mRNA strand…

3’ to 5’

FLIP it if it isn’t - he said in class he will try to trick us (EVIL)

Anti-codon

the bottom part of tRNA that pairs with the codons on the mature mRNA strand

amino acid binding cite

Top part of tRNA that attaches an amino acid (based on the codon the anti connects) to to polypeptide chain

Translation has 3 major needs,

tRNA

Ribosomes - large and small subunits

mRNA

What are the letters associated with Translation?

PAE

(You signed up for bio and now you’re going to PAE the price and study your ass off.)

The peptide bonds attached to the top of the tRNA are ______ using _______.

Anabolic using dehydration synthesis

The initiation stage is when ….

tRNA attaches at the start codon, starting the amino acid chain with MET

Does NOT include the large ribosome subunit

The elongation stage is when …

more tRNA is added onto the A site, the P site’s polypeptide chain adds to the top of that new one.

Then P releases and A becomes the P

The termination stage …

The release factor is on the stop codon, and the last tRNA releases from the P spot.

Then everything disassembles,

silent mutations

same amino acids

Neutral mutations

similar amino acids

Missense mutations

different amino acids

Nonsense

Stop codon

How man possible reading frames are there?

3