Anatomy of cell / Signal Transduction pathways (Harrison)

Question 1

What are the Lysomes?

Answer 1

Lysomes are the Enzymatic degradation of extracelllualr and intracellular macromolecules

Question 2

What is the nucleus?

Answer 2

DNA package with histones to form chromatin.

Question 3

RER?

Answer 3

Contains ribosomes for synthesizing proteins.

Question 4

What is the Golgi?

Answer 4

Site for protein folding, modification and sorting.

Question 5

What is the SER?

Answer 5

Synthesizes phospholipids, lipoproteins and sterols.

Question 6

What is the SER?

Answer 6

Synthesizes phospholipids, lipoproteins and sterols.

Question 7

What is the Mitochondrion?

Answer 7

Synthesizes ATP.

Question 8

What are Peroxysomes?

Answer 8

Synthesis and degradation of hydrogen peroxide?

Question 9

What are the purpose of microtubules and microfilaments?

Answer 9

Responsible for cell morphology and the machinery for movement of organelles

Question 10

What is the hydrophilic head and hydrophobic tail made of?

Answer 10

Hydrophilic head is made of a Phosphate function group and the hydrophobic tail is made of a Glycerol fatty acid chains.

Question 11

What is an IMP, compared to transmembrane?

Answer 11

An integral, or intrinsic, membrane protein is a type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins are IMPs, but not all IMPs are transmembrane proteins.

Most integral are transmembrane and have exposed portions on both sides.

Question 12

Heterochromatin vs Euchromatin

Answer 12

Heterochromatin (packaged tightly) is not actively transcribed into RNA, while euchromatin (loosely) is active transcribed into RNA.

Question 13

What are Receptor Tyrosine Kinases? Give an example of signal transduction with these

Answer 13

A class of transmembrane proteins that are important for signal transduction.

1. ) Inactive tyrosine kinase gets bound by single dimer.
2. ) Kinase activity is stimulated.,
3. ) Tyrosines are phosphorylated.
4. ) Intracellular proteins bind to phosphorylation-tyrosine docking sites.

Question 14

The fluid mosaic model tells us what about proteins in the cell membrane?

Answer 14

Proteins are constantly changing because of the dynamic bilayer.

Question 15

3 parts of the nucleus?

Answer 15

Nucleoplasm contains the genetic information, guarded by the Nuclear envelope, with nuclear pores that allow for selective exchange.

Question 16

Individual genes are present on __?

Answer 16

Only ONE chromosome,

There are 2 homologous chromosomes per cell, so two copies of each gene in a cell.

Question 17

Chromosome structure?

Answer 17

• Homologous chromosomes
• P arm
• Centromere
• q arm

Question 18

Total length of human genome in meters + microns, and the average size of a nucleus in microns?

Answer 18

Genome - 2 meters, 2,000,000 microns

Nucleus - 6 microns

Question 19

Histone charge? How many times does DNA loop? What are histones? What are nucleosomes

Answer 19

DNA wraps are 8 histones twice (histones are positively charged, DNA negatively) forming the nucleosome. Nucleosomes form building blocks of chromatin.

Question 20

What is the promotor region, exons, introns?

Answer 20

Promotor region - promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter.

Exons - transcribed

Introns - not transcribed

Question 21

What is at the beginning of the mRNA structure and at the end of it?

Answer 21

Untranslated regions - Start codon and stop codon.

Question 22

What is splice variation?

Answer 22

RNA splicing resulting in the loss of exons or the inclusion of introns and an altered protein-coding sequence. Also called splice-site mutation.

Question 23

What are codons? How are they numbered?

Answer 23

3 bases (nucleotides) called triplets that specify amino acids. Ada

Question 24

Cell communication?

Answer 24

Release of chemical message that is recognized by another cell.

Question 25

Describe signal transduction using primary messaging, ligand, and secondary messengers?

Answer 25

\*message may be directed to certain parts of the cell or even the nucleus to change gene expression via activation of transcription factors\*

Question 26

Describe Protein kinases, what are there targets and where do they target them specifically? What is a Dual specificity protein kinase?

Answer 26

Question 27

How is specificity achieved?

Answer 27

Question 28

Modification difference between protein phosphorylation and dephosphorylation?

Answer 28

Question 29

How is information often relayed? What can this result in?

Answer 29

This often results in massive signal amplification

Question 30

Describe 3 ways on how pathways may be activated by one or more stimuli?

Answer 30

This often results in massive signal amplification

Question 31

The relative activation of 1 pathway or another reps on “context”. Name 3 examples of this?

Answer 31

Question 32

What organizes the relative activation of 1 pathway or another? Describe how they do this?

Answer 32

Adaptor protein + signaling proteins = specific signaling complex

Question 33

Give a unspecific general example of scaffold protein? Also what is the proper nomenclature for displaying reaction pathways.

Answer 33

Adaptor protein + signaling proteins = specific signaling complex