Cell Organelles & Plasma Membrane - 1b

Question 1

What are organelles?

Answer 1

Tiny, specialised structures within the cytoplasm of the cell, each with a characteristic shape and specific function.

Question 2

What is the structure of mitochondria?

Answer 2

Bean-shaped with two membrane layers and a fluid-filled space between them, with the inner layer arranged into folds.

Question 3

What is the function of mitochondria?

Answer 3

Produces adenosine triphosphate (ATP) through aerobic cellular respiration, acting as a ready source of energy for the cell.

Question 4

What is the structure of ribosomes?

Answer 4

Consists of two sub-units made separately in the nucleolus and assembled in the cytoplasm; may be free or attached to the endoplasmic reticulum.

Question 5

What is the function of ribosomes?

Answer 5

Synthesises proteins used within the cell, inserted into the plasma membrane, or secreted out of the cell.

Question 6

What is the structure of rough endoplasmic reticulum?

Answer 6

A network of membrane-enclosed sacs, continuous with the nuclear membrane and studded with ribosomes.

Question 7

What is the function of rough endoplasmic reticulum?

Answer 7

Site for protein synthesis, sorting, processing, and delivering proteins throughout the cell.

Question 8

What is the structure of smooth endoplasmic reticulum?

Answer 8

A network of membranous tubules extending from the rough ER, with no ribosomes on its surface.

Question 9

What is the function of smooth endoplasmic reticulum?

Answer 9

Synthesises fatty acids and steroids, detoxifies drugs, and stores/releases calcium ions.

Question 10

What is the structure of the Golgi complex?

Answer 10

3-20 flattened membranous folds (cisternae) with bulging edges, typically curved with an entry and exit face.

Question 11

What is the function of the Golgi complex?

Answer 11

Modifies, sorts, and packages proteins for transport or secretion.

Question 12

What are lysosomes?

Answer 12

Small membrane-bound vesicles formed from the Golgi complex, containing powerful digestive enzymes.

Question 13

What is the function of lysosomes?

Answer 13

Digests and recycles substances from the cell and external sources.

Question 14

What are peroxisomes?

Answer 14

Smaller membrane-bound vesicles formed by the Golgi complex, containing oxidative enzymes.

Question 15

What is the function of peroxisomes?

Answer 15

Oxidises organic and toxic substances.

Question 16

What are proteasomes?

Answer 16

Tiny barrel-shaped structures made of stacked rings of protein.

Question 17

What is the function of proteasomes?

Answer 17

Continuous destruction of unneeded, damaged, or faulty cell proteins.

Question 18

What is the structure of centrosomes?

Answer 18

Two small perpendicular cylindrical centrioles surrounded by pericentriolar material.

Question 19

What is the function of centrosomes?

Answer 19

Makes microtubules in non-dividing cells and forms the mitotic spindle during cell division.

Question 20

What are cilia?

Answer 20

Short, numerous motile projections made of microtubules on the surface of some cells.

Question 21

What is the function of cilia?

Answer 21

Coordinated movement helps move substances across the cell surface.

Question 22

What is a flagellum?

Answer 22

A singular long motile projection made of microtubules on the surface of sperm cells.

Question 23

What is the function of a flagellum?

Answer 23

Whip-like movement helps propel the cell in fluid.

Question 24

What is the plasma membrane?

Answer 24

A flexible, sturdy barrier that surrounds the cytoplasm of the cell.

Question 25

What is the role of the plasma membrane?

Answer 25

Maintains homeostasis by controlling entry and exit of substances and providing protection.

Question 26

What are the components of the plasma membrane?

Answer 26

Consists of two layers of phospholipids, cholesterol, and glycolipids, with proteins attached.

Question 27

What are the types of membrane proteins?

Answer 27

Integral proteins and peripheral proteins.

Question 28

What is the function of integral proteins?

Answer 28

Extends into or completely across the cell membrane, not easily removed.

Question 29

What is the function of peripheral proteins?

Answer 29

Attached to membrane lipids or integral proteins, easily removed.

Question 30

What are the functions of membrane proteins?

Answer 30

Channels, carriers, enzymes, linkers, receptors, and cell identity markers.

Question 31

What is a concentration gradient?

Answer 31

Difference in concentration of substances in the cytosol and extracellular fluid.

Question 32

What is an electrical gradient?

Answer 32

Difference in distribution of charged ions across the cell membrane.

Question 33

What is an electrochemical gradient?

Answer 33

Combination of concentration and electrical gradients allowing transport of substances.

Question 34

What are the basic types of transport processes across the cell membrane?

Answer 34

Passive transport and active transport.

Question 35

What organelles work together to create and process protein?

Answer 35

Embedded Ribosomes, Rough ER & Golgi complexes.

Question 36

What is a vesicle?

Answer 36

A vesicle is a small spherical sac enclosed by membrane.

Question 37

What are the functions of vesicles?

Answer 37

Vesicles may be used for transport or storage.

Question 38

What determines the duration of storage in vesicles?

Answer 38

Storage may be short term or very long term, depending on the contents and purpose.

Question 39

How do vesicles compare to lysosomes?

Answer 39

Their appearance is the same as a lysosome; adding lysozyme enzymes to a vesicle will convert it into a lysosome.

Question 40

Are vesicles considered organelles?

Answer 40

Vesicles aren’t typically considered to be organelles, but they are important in cell processes.

Question 41

What does the smooth endoplasmic reticulum produce in the ovaries?

Answer 41

Produces oestrogen

Question 42

What is the function of mitochondria in skeletal muscle?

Answer 42

Produces large amounts of ATP for high energy needs

Question 43

What is the role of cilia in the lungs?

Answer 43

Moves mucus and trapped substances such as dust up out of the lungs

Question 44

What is the function of lysosomes?

Answer 44

Old or damaged cell structures are destroyed so that components can be recycled.

Question 45

What do peroxisomes do?

Answer 45

Organic substances are oxidised and toxic substances are broken down.

Question 46

What is the role of proteasomes?

Answer 46

Proteins are destroyed if they are faulty, too numerous or have completed their function.