Eukaryotic Cell Structure 2.4

Question 1

Nucleus

Answer 1

Biggest organelle in the cell. Stores all the genetic information that is used to code proteins. Controls protein synthesis and metabolic reactions.

Question 2

Nuclear envelope

Answer 2

A double membrane that surrounds the DNA and protects it from the cytoplasm

Question 3

Nuclear pores

Answer 3

Substances can leave and enter the nucleus

Question 4

Nucleolus

Answer 4

Part of the nucleus that produces ribosomes from ribosomal RNA and proteins

Question 5

Mitochondria

Answer 5

Main site of final stages of respiration. Energy is stored in the bonds of the complex and can be released by ATP. The inner membrane is highly folded and called cristae, the liquid inside is called the matrix. Has a small amount of DNA called mtDNA. Can make its own enzymes and reproduce itself

Question 6

Vesicles

Answer 6

They are like membranous sacs that are used to transport substances inside the cell. They also have a phospholipid bilayer

Question 7

Lysosomes

Answer 7

Specialised vesicles that contain hydrolytic enzymes that break down waste materials in the cell. They play an important role in the immune system.

Question 8

Cytoskeleton

Answer 8

Network of fibres present all throughout the cell and helps with cell stability and shape. it also controls movement of organelles and the actual cell.

Question 9

Microfilaments

Answer 9

These are fibres made of actin which are responsible for cell movement and cell contraction during cytokenesis.

Question 10

Microtubules

Answer 10

Made of tubulin and are scaffold like structures that determine the shape of the cell. They are also tracks for the movement of organelles like vesicles. Spindle fibres which are use for cell division are made of microtubules.

Question 11

Intermediate Fibres

Answer 11

Give strength and maintain integrity of cell

Question 12

Centrioles

Answer 12

Made of microtubules and when 2 of them are put together they form a centrosome which is used to assemble the spindle fibres for cell division.

Question 13

Flagella

Answer 13

Enable cells to move and are longer than cilia. They are good in sensory organelles

Question 14

Cilia

Answer 14

You can have stationary cilia which is present on many cell surfaces. Mobile cilia beats and gets rid of any mucus in air pipe. It also can move egg from ovary to uterus. Has a 9+2 arrangement, 2 main central centrioles and then 9 pairs on the outside, these overlap to create the beating motion.

Question 15

Smooth Endoplasmic Reticulum

Answer 15

Used to produce lipids, carbohydrates and hormones and is made from flattened sacs called cisternae. Also used for storage

Question 16

Rough Endoplasmic Reticulum

Answer 16

Used to synthesis and transport proteins. Has ribosomes bound to it.

Question 17

Ribosomes

Answer 17

Free floating in cytoplasm or bound to rough ER and are the site of protein synthesis, made of 2 subunits.

Question 18

Golgi Apparatus

Answer 18

Formed of cisternae similar to smooth ER and can modify and package proteins. These can then be released as secretory vesicles out of the cell or lysosomes which stay in the cell.