3.4 Eukaryotic Cell Functions

Question 1

Describe the structure of the plasma membrane

Answer 1

• double membrane with a bilayer between
• found on the surface of animal cells
• made of lipids and proteins

Question 2

Describe the structure of the nucleus

Answer 2

• large organelle surrounded by a nuclear envelope (double membrane) which contains pores
• nucleolus which contains chromosomes consisting of protein-bound, linear DNA

Question 3

Describe the structure of mitochondria

Answer 3

• oval-shaped
• surrounded by a double membrane
• extensions of cristae in the inner membrane
• the matrix, has enzymes involved in respiration

Question 4

Describe the structure of chloroplasts

Answer 4

• small, flattened structure found in plant and algal cells
• surrounded by a double membrane
• grana full of stacks of thylakoid membranes that contains chlorophyll for photosynthesis
• grana are linked together by lamellae, thin flat pieces of thylakoid membrane

Question 5

Describe the structure of the Golgi apparatus

Answer 5

• group of fluid-filled membrane-bound flattened sacs
• vesicles are found on the edges of the sacs

Question 6

Describe the structure of the Golgi vesicles

Answer 6

• small fluid-filled sacs in the cytoplasm
• surround by a membrane
• produced by Golgi apparatus

Question 7

Describe the structure of lysosomes

Answer 7

• round organelle surrounded by a membrane
• no clear internal structure
• type of Golgi vesicle

Question 8

Describe the structure of ribosomes

Answer 8

• very small organelle
• either floats free or attached to the RER
• made of proteins and RNA
• has NO membrane
• two types: 80S & 70S

Question 9

Describe the structure of the rough endoplasmic reticulum (RER)

Answer 9

• system of membranes
• enclose a network of tubules and flattened sacs called cisternae
• ribosomes on outside

Question 10

Describe the structure of the smooth endoplasmic reticulum (SER)

Answer 10

• system of membranes
• enclose a network of tubules and flattened sacs called cisternae
• no ribosomes

Question 11

Describe the structure of the cell wall

Answer 11

• rigid structure that surrounds cells in plants, algal and fungi
• PLANTS AND AGAL: made of microfibrils of cellulose, embedded in the matrix
• FUNGI: made of chitin
• thin layer that marks boundary between adjacent cell walls and cements adjacent cells together called the middle lamella

Question 12

Describe the structure of the cell vacuole

Answer 12

• fluid-filled sac bound by a single membrane called the tonoplast
• found in plant cells
• contains a solution of mineral salts, sugars, amino acids, wastes and sometimes pigments called cell sap