Organelles of Eukaryotics

Question 1

What does the plasma membrane do?

Answer 1

Surrounds the cell and defines structure

Question 2

What do ions and glucose require to cross the plasma membrane?

Answer 2

Protein channels or transporters

Question 3

Why is selective transport important?

Answer 3

Keeps biochemical conditions inside the cell favourable

Question 4

What does selective transport allow for?

Answer 4

A concentration gradient

Question 5

What is a concentration gradient across a plasma membrane important for?

Answer 5

Firing of nerve cells and contraction of muscle cells

Question 6

What is plasma membrane made of?

Answer 6

Phospholipids, proteins, cholesterol and glycolipids

Question 7

Why do phospholipids create a lipid bilayer?

Answer 7

They are ampiphatic

Question 8

What does a lipid bilayer in plasma membrane allow for?

Answer 8

Rotation and lateral movement of phospholipids and proteins

Question 9

Why is fluidity important in plasma membrane?

Answer 9

To allow for cell migration and membrane repair

Question 10

What type of protein are found in plasma membrane?

Answer 10

Receptors and ion channels

Question 11

What are the shapes of protein receptors specific to?

Answer 11

The shape of ligands such as hormones, drugs or toxins

Question 12

Why are protein important in plasma membrane?

Answer 12

Allow for cell to interact with external environment and for transport

Question 13

Where does transcription take place?

Answer 13

In the nucleus

Question 14

What is mRNA used for?

Answer 14

Assembling a protein in translation

Question 15

What is the bulk of nucleus filled with?

Answer 15

Chromatins

Question 16

What is the nucleus membrane made of?

Answer 16

2 lipid bilayers

Question 17

What is the outer membrane of the nucleus membrane continuous with?

Answer 17

Endoplasmic Reticulum

Question 18

What is the function of ER?

Answer 18

The translation of proteins destine for membrane or secretion

Question 19

What happens to proteins that are secreted from ER to Rough ER?

Answer 19

They undergo post-translational modifications such as addition of a sugar group

Question 20

What is budding?

Answer 20

When small vesicles break off from the ER and fuse with the Golgi

Question 21

How goes the Golgi communicate?

Answer 21

Through budding

Question 22

How are vesicles formed?

Answer 22

Through the budding process

Question 23

What are lysosomes responsible for?

Answer 23

General destruction of debris and bacteria

Question 24

What do lysosomes rely on?

Answer 24

Action of acid hydrolase with the vesicle

Question 25

What are proteasome responsible for?

Answer 25

Targeted degradation of specific proteins

Question 26

Where are proteasome found?

Answer 26

In the cytoplasm and nucleus

Question 27

Why may proteins need degradation removed by proteasome?

Answer 27

Due to incorrect folding or too high concentration of protein

Question 28

What is added to a target protein as a marker for degradation?

Answer 28

A protein ubiquitin

Question 29

What do mitochondria produce?

Answer 29

Large amounts of ATP

Question 30

What is the purpose of cytoskeleton?

Answer 30

To provide protein scaffolding

Question 31

How is cytoskeleton highly dynamic?

Answer 31

By coordinated assembly and disassembly of fibres

Question 32

How do vesicles move around the cell?

Answer 32

They are attached to microtubules which lengthen and shorten to pull them around the cell

Question 33

What is special about the nucleolus?

Answer 33

It is a region of the nucleus with no membrane

Question 34

What is in the nucleolus?

Answer 34

Condensed chromatin with DNA that codes for RNA

Question 35

What must large molecules have to pass in and out of the nucleus?

Answer 35

Nuclear localisation key sequence

Question 36

What do free ribosomes do?

Answer 36

Translate cytoplasmic proteins

Question 37

What is the process of translating cytoplasmic proteins?

Answer 37

1. Protein folds as it emerges from ribosome and gets stuck in the cytosol
2. Proteins which need to leave the cell or embed in membrane are translated to attach to ER
3. The proteins are then transported in vesicles to the cell surface