Lecture 11 - Nucleus And Protem Synthesis

Question 1

Nucleus

Answer 1

Largest organelle, contains genetic library for the synthesis of nearly all cellular proteins and response to signals that dictate kinds and amounts of protein to be synthesized

Question 2

Uninucleate

Answer 2

One nucleus (most cells)

Question 3

Multinucleate

Answer 3

Many nuclei (skeletal muscle,certain bone cells and some liver cells)

Question 4

Anucleate

Answer 4

No nucleus (red blood cells)

Question 5

Nucleus structure

Answer 5

Nuclear envelope
Nucleoli
Chromatin

See slides for diagram

Question 6

Nuclear envelope

Answer 6

Double membrane barrier surrounding nucleus

Question 7

Nuclear pores

Answer 7

Regulate passage of large particles in and out of cell

Question 8

Nucleoli

Answer 8

Dark staining spherical bodies within a nucleus
Sites of assembly of two ribosomal subunits

Question 9

Chromatin

Answer 9

Made of nucleosomes ( 8 Clusters of histone proteins) 
Prevents tangles

When cell divides, chromatin condenses into Rod like chromosomes to protect itself

Question 10

Junk DNA

Answer 10

Non-coding portion of DNA
98% does not encode proteins

Much functions by regulating gene expression

Question 11

Transcription factors

Answer 11

Regulatory elements that affect when and how often each of your genes are expressed

Question 12

Activator proteins

Answer 12

Bind two stretches of DNA regions called enhancers to encourage transcription

Affected genes = upregulated 

Question 13

Repressors and silencers

Answer 13

Discourage expression of Gene

Downregulated

Question 14

Gene

Answer 14

Segment of DNA that carries instructions for one polypeptide chain

Question 15

Triplet

Answer 15

Sequence of three nucleotide bases of DNA

Specifies an amino acid in sequence that make up a protein

Question 16

Exons

Answer 16

Part of a gene that code for amino acids

Question 17

Introns

Answer 17

Non coding segments interspersed amongst exons

Question 18

Transcription

Answer 18

DNA to RNA
Copy sequence of nucleotide, make mRNA strand

Process of transferring info from genes DNA to complementary mRNA

RNA polymerase unzips DNA synthesizing mRNA strand

Question 19

Translation

Answer 19

New!

Process of converting nucleotides to amino acids
tRNA picks up amino acid from cytoplasm, binds to mRNA, transfers to ribosome to be attached to growing protein strand

Question 20

Messenger RNA (mRNA)

Answer 20

Copies sequence of DNA
Codon - Three base sequence of mRNA and lines up with DNA triplet

Question 21

Transfer RNA (tRNA)

Answer 21

Carries amino acid to corresponding codon

Question 22

Ribosome RNA (rRNA)

Answer 22

Temporarily binds to mRNA and tRNA in ribosome catalyzing the reaction to bind amino acid to polypeptide chain

Question 23

Splicing

Answer 23

Before mRNA leaves nucleus introns are cut out and exons are reconnected

Alternative splicing- Cuts out some exons as well as introns, allowing one gene to make different proteins

Question 24

REVIEW LECTURE #11 FOR DIAGRAMS.