Lecture 1: Introduction to Cell biology

Question 1

Level of organization:

Answer 1

atms → molecules → organelles → cells → tissues → organ systems → organism → ecosystem

Question 2

Function of each level depends on what?

Answer 2

the organization and number of organelles

Question 3

Organelles:
What is the function of cytosol

Answer 3

metabolism, protein synthesis via free ribosomes

Question 4

What is the function of the cytoskeleton

Answer 4

Cell shape and movement, intracellular transport

Question 5

What is the function of the nucleus

Answer 5

to carry the genome (22 autosomes and 2 sex chromosomes)
DNA and RNA synthesis

Question 6

What is the function of the mitochondria

Answer 6

atp synthesis by oxidative phosphorylation

Question 7

What is the function of the smooth endoplasmic reticulum

Answer 7

synthesis of lipids and ca 2+ storage

Question 8

What is the function of ribosomes

Answer 8

translation of mRNA into proteins

Question 9

What is the function of lysosomes

Answer 9

intracellular degradation

Question 10

What is the function of endosomes

Answer 10

cellular uptake of cholesterol, removal of receptors from plasma membrane, uptake of small molecules and water into the cell, internalization of large particles (bacteria, cell debris)

Question 11

what is the function of Golgi apparatus

Answer 11

Modification, sorting, and packing of protein and lipids for delivery to other organelles within the cell or for secretion out of the cell

Question 12

What is the function of the proteasome

Answer 12

degradation of intracellular proteins

Question 13

what is the function of peroxisome

Answer 13

detoxification of substances

Question 14

Proteins leaves the cell and follow the _____________

Answer 14

secretory pathway

Question 15

What are the steps of the secretary pathway

Answer 15

1. synthesis in RER ribosomes
2. transport to SER and modification
3. Transport through the Golgi with further modification
4. Placement in secretory vesicles

Question 16

What happens at the site of ribosomes

Answer 16

Translation (RNA —> Protein)

Question 17

What are thee two subunits in animals cells that are the site of translation

Answer 17

40s and 60s

Question 18

____________ codon is occupied by peptidyl tRNA which carries the chain of amino acids (process)

Answer 18

P site

Question 19

___________ binds incoming aminoacyl tRNA directed by the codon occupying the site

Answer 19

A site

Question 20

___________ empty tRNA about to exit

Answer 20

E siite

Question 21

___________ extends from the Nucleus

Answer 21

Endoplasmic reticulum

Question 22

What is the destiny of proteins translated in the rough endoplasmic reticulum

Answer 22

1. Inside the organelles
2. membranes of cells or organelles
3. Secretion

Question 23

What does the smooth endoplasmic reticulum do

Answer 23

makes steroids and breaks down toxins

Question 24

Where is cytochrome P450 enzymes located

Answer 24

in the membrane of SER

*very large in steroid homone producing cells such as hepatocytes

Question 25

______________ a distribution center, adds signals for sorting and sending vesicles towards the cell membrane (trans) and back toward ER (cis)

Answer 25

Golgi apparatus

Question 26

What are some post translational modification (SF11) that occurs in the Golgi

Answer 26

1. adding O oligosaccrides on serine and threonine
2. Modifying N oligosaccharides on asparagine
3. Tagging proteins for final destinations

Question 27

_____________ degrade contents, deformed out of endoscope by addition of digestive enzymes and ph regulating membrane channels. Can rise with other vesicles (phagosomes and autophagosomes) for digestion

Answer 27

Lisosomes