3.2.1..1 Structure of eukaryotic cells

What organisms are eukaryotic?

• Animals

• Plants

• Algal

• Fungal

What organelles do plant cells have that animal cells don’t?

• Cellulose wall with plasmodesmata (channels for exchanging substances between adjacent cells)

• Vacuole

• Chloroplasts

What organelles do plant and animal cells both have?

• Cell-surface plasma membrane

• Rough endoplasmic reticulum

• Lysosomes

• Ribosomes

• Nuclear envelope

• Golgi apparatus

• Cytoplasm

• Mitochondrion

• Nucleus

• Nucleolus

• Smooth endoplasmic reticulum

What are the difference between plant cells and algal cells?

• Algal cells can be either unicellular or multicellular

• The chloroplasts in many algal cells are a different shape and size to those in plant cells

• E.g. some algae have one large chloroplast rather than several smaller chloroplasts

What are the 2 differences between fungal and plant cells?

• Fungal cell walls are made of chitin, not cellulose

• Fungal cells do not have chloroplasts because they don’t photosynthesise

Cell-surface membrane - description

• The membrane found on the surface of animal cells and just inside the cell wall of other cells

• It is made mainly of lipids and proteins

Cell-surface membrane - function

It regulates the movement of substances into and out of the cell. It also has receptor molecules on it, which allow it to respond to chemicals like hormones

Nucleus - description

• A large organelle surrounded by a nuclear envelope (double membrane), which contains many pores

• It contains chromosomes and nucleolus

Nucleus - function

• It controls the cell’s activities (by controlling the transcription of DNA)

• DNA contains instructions to make proteins

• The pores allow substances to move between the nucleus and the cytoplasm

• The nucleolus makes ribosomes

Mitochondrion - description

• Usually oval shaped

• Double membrane- the inner one is folded to form structures called cristae

• Inside is the matrix, which contains enzymes involved in respiration

Mitochondrion - function

• The site of aerobic respiration

• Aerobic respiration produces ATP

• Mitochondria are found in large number of cells that are very active and require a lot of energy