Eukaryotic Cell Structure

Question 1

Name the organelles in the endomembrane system

Answer 1

Nucleus, endoplasmic reticulum, golgi apparatus, lysosomes

Question 2

Function of the nucleus

Answer 2

storage of DNA, site of gene expression

Question 3

Function of the nucleolus

Answer 3

site of ribosomal subunit assembly (large and small protein components associate with their rRNAs)

Question 4

When do ribosomes subunits come together

Answer 4

When they leave the nucleus, come together in cytoplasm (protect DNA)

Question 5

Function and structure of the nuclear envelope

Answer 5

Separates nucleoplasm from cytoplasm (protect DNA)

Consists of two lipid bilayers + nuclear lamina

Question 6

In DNA packaging, what histone stacks the nucleosomes

Answer 6

H1

Question 7

What happens to chromatin during packaging

Answer 7

turns into chromosome

Question 8

Difference between centromere, chromatid, chromatin, chromosome, centrosome, centrioles

Answer 8

Centromere: where sister chromatids are linked
Chromatid: half a chromosome
Chromosome: DNA molecule
Chromatin: DNA & protein, chromosome pre-packaging
Centrosome: organelle, microtubule organizing center
Centrioles: organelle made of tubulin, makes up centrosome

Question 9

Rough ER are found in the endomembrane system, they are covered in _________, these are called ____________, they make proteins destined for ____________________.

Answer 9

1. ribosomes
2. Bound ribosomes
3. endomembrane system

Question 10

Function of rough ER

Answer 10

site of protein synthesis for proteins that function within the endomembrane system
site of protein control (chaperones)

Question 11

Where are free ribosomes found

Answer 11

In the cytoplasm

Question 12

Function of the smooth ER

Answer 12

ion storage, phospholipid synthesis, steroid synthesis, detoxification of drugs and alcohol

Question 13

Function of the Golgi apparatus

Answer 13

receives cargo from ER, sorts to different destinations (lysosome, plasma membrane, back to ER), packages cargo into vesicles
“fed ex” of the cell

Question 14

What are the two models of Golgi Trafficking, explain briefly

Answer 14

1) Vesicle trafficking: vesicle fuses with cis, cargo is transferred from cis to medial to trans Golgi in vesicles
2) Cisternal Maturation: cis becomes medial, medial becomes trans, trans splits into vesicles. New cisternae forms by fusion of vesicles from ER

Question 15

Function of the lysosome as the “cell stomach”, its ideal pH and how it maintains it

Answer 15

digestion of macromolecules from endocytosis, contains hydrolytic enzymes that function best at pH=5 (constantly pumped H+ in to maintain low pH)

Question 16

Function of lysosome as autophagy

Answer 16

autophagy= self eating

organelle recycling, but also so a cell can commit suicide by rupturing lysosome (apoptosis)

Question 17

What happens during lysosomal storage disorders

Answer 17

patient lacks enzyme to digest a particular lipid, it accumulates and causes neuronal cell death

Question 18

Three functions of vacuoles

Answer 18

food vacuoles, contractile vacuoles (pump out excess water), central vacuole (in plants-storage)

Question 19

Name the organelles not in the endomembrane system

Answer 19

mitochondria, chloroplasts, peroxisomes, cytoskeleton

Question 20

What are peroxisomes involved in

Answer 20

detox of alcohols, metabolism of fats

Question 21

Name the different types of fibers in the cytoskeleton

Answer 21

microtubules, microfilaments, intermediate filaments

Question 22

Function/Structure of microtubules

Answer 22

Compression resistance, polymers of tubulin

ex. Eukaryotic flagellum

Question 23

Function/Characteristics of Eukaryotic Flagellum

Answer 23

Cell movement, powered by ATP hydrolysis, membrane bound, whip-like, movement generated by dyenin

Question 24

Structure/Function of Microfilaments, polymer of ____. Motor: _____

Answer 24

polymer of actin, tension resistance, movement (muscular contraction), motor: myosin
ex. Sarcomere (contractile unit of the muscle)

Question 25

Structure/Function of Intermediate Filaments

Answer 25

many diff subunit types that form rope like filaments, tension resistance

ex. laminin (forms the nuclear lamina)
ex. Keratin: hair and nails