2.1.1 Ultrastructure of Eukaryotic Cells

Question 1

Structure of the Nuclear Envelope

Answer 1

• Double membrane structure with a number of pores
• Inner and outer embranes are phospholipid bilayers

Question 2

Function of the Nuclear Envelope

Answer 2

• Pores in the nuclear envlelope control the passage of ions, molecules and RNA between nucleoplasm and cytoplasm

Question 3

Structure of the Nucleus

Answer 3

• Nucleoplasm (semi-solid fluid where nucleolus and chromatin are found)
• Linear chromosomes(eukaryotes) made up of DNA
• Nucleolus

Question 4

Function of the Nucleus

Answer 4

• Controls the activities of the cell
• DNA contains instructions for the synthesis of proteins
• rRNA is joined together with associated proteins in the nucleolus to assemble ribosomal subunits

Question 5

Structure of the nucleolus

Answer 5

• Largest substructure within the nucleus
• Made up of proteins, DNA and RNA

Question 6

Function of the Nucleolus

Answer 6

• Site at which ribosomes are made
• Secondary roles such as immobilising proteins and forming signal recognition particles

Question 7

Structure of Mitochondria

Answer 7

• Oval shaped
• Double membrane organelles
• Make their own DNA and ribosomes
• Cristae(folds in the inner layer)
• Matrix(surrounding the folds)
• Matrix contains enzymes used for respiration

Question 8

Function of Mitochondria

Answer 8

• Produce ATP via aerobic respiration

Question 9

Structure of Chloroplasts

Answer 9

• Have their own DNA, ribosomes and inner and outer membranes
• Inner membrane surrounds thylakoids(interconnected and stacked fluid-filled membranes)
• Granum(each stack)
• Lamallae(link the granum)
• Stroma(fluid that surrounds grana)

Question 10

Function of chloroplasts

Answer 10

• Photosynthesis
• ## Allows plants to make their own food