3.2.1.1 Structure of eukaryotic cells
23 December 2020 18:37
The structure of eukaryotic cells, restricted to the structure and function of:
• cell-surface membrane
Made from phospholipids
• nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or
more nucleoli)
Double membrane called the nuclear envelope containing nuclear pores that enables molecules to enter and
leave. It also contains chromatin and a nucleolus which is the site of ribosome production. A granular jelly like
material called nucleoplasm makes up the bulk of the nucleus.
• mitochondria
oval shaped, bound by a double membrane called the envelope. Have 70s ribosomes. The inner membrane is
folded to form projections called cristae with a matrix on the inside containing all the enzymes needed for
respiration. Releases energy through aerobic respiration.
• Golgi apparatus and Golgi vesicles
A series of fluid filled, flattened & curved sacs with vesicles surrounding the edges. Golgi apparatus processes and
packages proteins and lipids. It also produces lysosomes.
• lysosomes (a type of Golgi vesicle that releases lysozymes)
Lysosomes are vesicles containing digestive enzymes bound by a single membrane.
Cells Page 1
,• ribosomes
80s Ribosomes are composed of RNA and proteins and are the site of protein production.
• rough endoplasmic reticulum and smooth endoplasmic reticulum
Rough endoplasmic reticulum is a series of flattened sacs enclosed by a membrane with ribosomes on the surface.
RER folds and processes proteins made on the ribosomes.
Smooth endoplasmic reticulum is a system of membrane bound sacs. SER produces and processes lipids.
• chloroplasts (in plants and algae)
Has stacks of granum (thylakoids) surrounded by stroma and thylakoids are joined by intergranular lamella, has 70s
ribosomes. Site of photosynthesis.
• cell wall (in plants, algae and fungi)
A cell wall is a rigid, semi-permeable protective layer. Functions to protect, support.
• cell vacuole (in plants)
In complex multicellular organisms, eukaryotic cells become specialised for specific
functions. Specialised cells are organised into tissues, tissues into organs and organs into
systems. Students should be able to apply their knowledge of these features in explaining
adaptations of eukaryotic cells.
Cells Page 2
, 3.2.1.2 Structure of prokaryotic cells and of viruses
23 December 2020 18:52
Prokaryotic cells are much smaller than eukaryotic cells. They also differ from
eukaryotic cells in having:
• cytoplasm that lacks membrane-bound organelles
• smaller ribosomes (70s not 80s)
• no nucleus; instead they have a single circular DNA molecule that is free in
the cytoplasm and is not associated with proteins
• a cell wall that contains murein, a glycoprotein.
In addition, many prokaryotic cells have:
• one or more plasmids
• a capsule surrounding the cell
• one or more flagella.
Details of these structural differences are not required.
Viruses are acellular and non-living.
The structure of virus particles to include genetic material, capsid and
attachment protein.
Cells Page 3
23 December 2020 18:37
The structure of eukaryotic cells, restricted to the structure and function of:
• cell-surface membrane
Made from phospholipids
• nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or
more nucleoli)
Double membrane called the nuclear envelope containing nuclear pores that enables molecules to enter and
leave. It also contains chromatin and a nucleolus which is the site of ribosome production. A granular jelly like
material called nucleoplasm makes up the bulk of the nucleus.
• mitochondria
oval shaped, bound by a double membrane called the envelope. Have 70s ribosomes. The inner membrane is
folded to form projections called cristae with a matrix on the inside containing all the enzymes needed for
respiration. Releases energy through aerobic respiration.
• Golgi apparatus and Golgi vesicles
A series of fluid filled, flattened & curved sacs with vesicles surrounding the edges. Golgi apparatus processes and
packages proteins and lipids. It also produces lysosomes.
• lysosomes (a type of Golgi vesicle that releases lysozymes)
Lysosomes are vesicles containing digestive enzymes bound by a single membrane.
Cells Page 1
,• ribosomes
80s Ribosomes are composed of RNA and proteins and are the site of protein production.
• rough endoplasmic reticulum and smooth endoplasmic reticulum
Rough endoplasmic reticulum is a series of flattened sacs enclosed by a membrane with ribosomes on the surface.
RER folds and processes proteins made on the ribosomes.
Smooth endoplasmic reticulum is a system of membrane bound sacs. SER produces and processes lipids.
• chloroplasts (in plants and algae)
Has stacks of granum (thylakoids) surrounded by stroma and thylakoids are joined by intergranular lamella, has 70s
ribosomes. Site of photosynthesis.
• cell wall (in plants, algae and fungi)
A cell wall is a rigid, semi-permeable protective layer. Functions to protect, support.
• cell vacuole (in plants)
In complex multicellular organisms, eukaryotic cells become specialised for specific
functions. Specialised cells are organised into tissues, tissues into organs and organs into
systems. Students should be able to apply their knowledge of these features in explaining
adaptations of eukaryotic cells.
Cells Page 2
, 3.2.1.2 Structure of prokaryotic cells and of viruses
23 December 2020 18:52
Prokaryotic cells are much smaller than eukaryotic cells. They also differ from
eukaryotic cells in having:
• cytoplasm that lacks membrane-bound organelles
• smaller ribosomes (70s not 80s)
• no nucleus; instead they have a single circular DNA molecule that is free in
the cytoplasm and is not associated with proteins
• a cell wall that contains murein, a glycoprotein.
In addition, many prokaryotic cells have:
• one or more plasmids
• a capsule surrounding the cell
• one or more flagella.
Details of these structural differences are not required.
Viruses are acellular and non-living.
The structure of virus particles to include genetic material, capsid and
attachment protein.
Cells Page 3
