Cell Structure

Question 1

Cytoplasm

Answer 1

term used for the cytosol (fluid) plus the organelles suspended within the cytosol.

Question 2

Cytosol (intracellular fluid)

Answer 2

fluid (solvent) within which all the other cell organelles float. The cytosol is mostly water but has solutes dissolved and suspended in it.

Question 3

Organelles

Answer 3

metabolic machinery of the cell. These are membranous structures with specialised functions.

Question 4

Inclusions

Answer 4

These may be present depending on cell type. Examples of inclusions are stored nutrients such as lipid in fat cells, and pigment granules in some skin cells.

Question 5

Plasma Membrane

Answer 5

A double layer of phospholipids with hydrophilic heads and hydrophobic tails, bound with proteins, cholesterol and carbohydrates.

Question 6

Phospholipid

Answer 6

Bilayer of lipids

Question 7

Hydrophilic

Answer 7

Water loving and polar

Question 8

Hydrophobic

Answer 8

Water hating and non-polar

Question 9

Functions of the Plasma Membrane

Answer 9

1. Transport
   
   2. Enzymatic activity
   3. Signal transduction
   4. Cell to cell recognition
   5. Intercellular joining
   6. Attachment to the cytoskeleton ECM

Question 10

Mitochondria

Answer 10

Double membraned cristae that create energy (ATP) to function cells

Question 11

Cristae

Answer 11

Double membrane that is folded with the inner membrane being smooth.

Question 12

ATP

Answer 12

Adenosine triphosphate is an energy carrying molecule that is used in cells that release quick energy.

Question 13

ADP

Answer 13

Adenosine diphosphate is an energy carrying molecule after ATP has been broken down and is a low energy molecule.

Question 14

Centrosome

Answer 14

A area where two groups of microtubules (centrioles) are found.

Question 15

Golgi Apparatus

Answer 15

A membranous structure with one membrane that it flat and packages and modifies proteins and lipids to transport them to other cells.

Question 16

Vacuoles

Answer 16

Parts of golgi apparatus that have broken off and play a role in intracellular digestion and the release of cellular waste.

Question 17

Lysosomes

Answer 17

Contains enzymes necessary for intracellular digestion.

Question 18

Peroxisomes

Answer 18

Enzymes with their main function to break down hydrogen peroxide into water and oxygen.

Question 19

Ribosomes

Answer 19

Small round structures that either float around in the cytosol or attached to the endoplasmic reticulum and synthesis proteins

Question 20

Smooth Endoplasmic Reticulum

Answer 20

The smooth endoplasmic reticulum (ER) is a continuation of the outer nuclear membrane and is a vast network of membranous vesicles and tubules. It is called smooth because it appears smooth when looking through an electron microscope.
The functions include lipid and steroid hormone synthesis, breakdown of lipid-soluble toxins in liver cells, and control of calcium in muscle cell for contraction.

Question 21

Rough Endoplasmic Reticulum

Answer 21

Rough endoplasmic reticulum (ER) appears uneven under the electron microscope because of the numerous ribosomes on the surface.
Proteins synthesized by the ribosomes are collected in the rough endoplasmic reticulum and are then transported throughout the cell.

Question 22

Cytoskeleton

Answer 22

consists of microtubules and microfilamants which help to maintain cell shape. Some cells have hair-like projections from the plasma membrane with microtubules inside them. Another function of the cytoskeleton is cell motility. This includes the internal movement of cell organelles, cell division and muscle fiber contraction, as well as the locomotion of some cells eg sperm.

Question 23

Nucleus

Answer 23

surrounded by a double membrane (envelope) with large pores which allows for communication with the surrounding cytosol. Inside the nucleus is nuclear chromatin, the entire genetic material in a human. The nucleolus is a big structure inside the nucleus which produces ribosomes. The ribosomes then move out of the nucleus into the cytosol where some attach to the endoplasmic reticulum.