Structure Of Eukaryotic Cells (3.2.1.1)

Question 1

What are cells?

Answer 1

• The basic units of living organisms

Question 2

What are the two main groups of cellular organisms?

Answer 2

• Eukaryotes
• Prokaryotes

Question 3

What organelles are found in eukaryotic cells?

Answer 3

• Cell-surface membrane
• Nucleus
• Mitochondria
• Smooth endoplasmic reticulum
• Rough endoplasmic reticulum
• Golgi apparatus
• Golgi vesicles
• Ribosomes
• Lysosomes
• Chloroplasts
• Cell wall
• Cell vacuole

Question 4

Describe the structure and function of the cell-surface membrane

Answer 4

• A phospholipid bilayer
• Controls the entrance and exit of molecules

Question 5

Describe the structure and function of the nucleus

Answer 5

• Surrounded by a nuclear envelope (double membrane), which contains pores. Inside, the nucleus contains chromatin, DNA and proteins, and a nucleolus
• Contains the genetic material, site of DNA replication and transcription

Question 6

Describe the structure and function of the mitochondria

Answer 6

• Double membrane structure, the inner membrane folds to form cristae, providing a large surface area. The inner matrix contains enzymes for respiration
• Site of aerobic respiration and ATP production

Question 7

Describe the structure and function of the smooth endoplasmic reticulum

Answer 7

• A system of membrane-bound sacs
• Production and transport of lipids

Question 8

Describe the structure and function of the rough endoplasmic reticulum

Answer 8

• A system of membrane-bound sacs enclosing a fluid-filled space. The surface is covered with ribosomes
• Folds and processes proteins for transport to the golgi apparatus

Question 9

Describe the structure and function of the golgi apparatus

Answer 9

• Flattened membrane-bound sacs
• Processes and packages proteins and lipids, produces lysosomes and forms glycoproteins by adding carbohydrates to proteins received from the RER

Question 10

Describe the structure and function of the golgi vesicles

Answer 10

• Small membrane-bound sacs produced by the golgi apparatus
• Stores and transports modified proteins and lipids from the golgi apparatus to various destinations

Question 11

Describe the structure and function of the ribosomes

Answer 11

• Two sub-units of proteins and rRNA, free or attached to the RER
• Site of protein synthesis

Question 12

What are the types of ribosomes and where are they found?

Answer 12

• 70S and 80S
• 70S in prokaryotes, mitochondria and chloroplasts, 80S in cytoplasm and RER

Question 13

Describe the structure and function of the lysosomes

Answer 13

• Membrane-bound vesicles containing hydrolytic enzymes
• Digestion of old organelles, hydrolysis of material ingested by phagocytosis and the release of enzymes outside the cell

Question 14

Describe the structure and function of the chloroplasts

Answer 14

• Surrounded by a double membrane. Inside contains thylakoids, which in places form stacks called grana and the stroma, which contains enzymes for photosynthesis
• Site of photosynthesis

Question 15

Describe the structure and function of the cell wall

Answer 15

• In plants made up of cellulose, in fungi made of chitin
• Providing support, strength and shape to the cell

Question 16

Describe the structure and function of the cell vacuole

Answer 16

• Contains cell sap and is surrounded by a single membrane called a tonoplast
• Maintains cell turgidity and provides support