Prokaryotic and Eukaryotic Cells

Question 1

Structure - EKY

Answer 1

Eukaryotic cells:

• much larger than PKY
• contain membrane-bound, fluid-filled compartments –> organelles

Question 2

Structure - PKY

Answer 2

PKY cells:

- have a cell wall, cell membrane, cytoplasm, ribosomes and a single, circular chromosome –> nucleoid

Question 3

Nucleus

Answer 3

• large organelle surrounded by cell wall/membrane
• contains most of the genetic info (DNA) of the cell
• often called the control centre of the cell
• DNA contains coded instructions for building proteins –> control everything that happens in a cell

Question 4

Ribosomes

Answer 4

• non-membrane bound organelles
• made up of 60% rRNA and 40% protein
• where proteins are synthesised –> read the genetic code from mRNA

Question 5

Rough Endoplasmic Reticulum

Answer 5

• network of membranous channels within a cell
• materials are transported through the ER
• rough because it is dotted with ribosomes

Question 6

Mitochondria

Answer 6

• an organelle surrounded by a double membrane
• contains own DNA on circular chromosome and ribosomes to synthesise its own proteins
• the site of aerobic cellular respiration –> energy is released from glucose in the form of ATP

Question 7

Golgi Apparatus

Answer 7

• a stack of flattened membrane-bound sacs

Function:
- modify and package proteins for export from the cell

Question 8

Centrioles

Answer 8

• only in animal cells –> contain two centrioles arranged at right angles to each other –> centrosome
• during mitosis/meiosis, the centrioles move apart to opposite sides of the cell –> help efficiently organise the spindle fibres

Question 9

Cilium or Flagellum

Answer 9

• external structure consisting of microtubules

Function:

Motility - movement of substances across cell surface

Question 10

Chloroplasts

Answer 10

• large organelles bound by two layers of membrane –> only found in plant cells
• contains thylakoids –> stacked in grana –> fluid between them are called stroma
• contains chlorophyll and are the site of photosynthesis

Question 11

Large Vacuole

Answer 11

• a membrane-bound sac containing water and dissolved ions –> only found in plant cells

Function:

• to create turgor pressure which gives plant structure
• stores metabolic wastes from the cell

Question 12

Cytoplasm/Cytosol

Answer 12

Cytosol:
- the fluid in which the organelles of the cytoplasm are suspended

Cytoplasm :

• everything that lies between the nuclear envelope and the plasma membrane
• includes all the organelles except the nucleus