Structure of eukaryotic cells Flashcards
What is a eukaryotic cell?
Eukaryotic cells are complex cells that contain a nucleus and other membrane-bound organelles
Where are eukaryotic cells found?
In multi-cellular organisms such as animals, plants and fungi
What is the structure of the cell-surface membrane?
- Mainly made of lipids and protein
What is the function of the cell-surface membrane?
- Regulates the movement of substances into and out of the cell
- Has receptor molecules on it which allow it to respond to chemicals like hormones
What is the structure of the nucleus?
- Surrounded by a nuclear envelope which contains many pores (double membrane)
- Contains chromosomes made from protein-bound linear DNA
- Contains one or more nucleolus
What is the function of the nucleus?
- Controls the cells activities
- The pores in nuclear envelope allow substances like RNA to move between nucleolus and cytoplasm
- The nucleolus makes ribosome
What is the structure of the mitochondria?
- Oval shaped
- Has a double membrane
- Inner membrane folded to form structures called cristae
- Inside inner membrane is the matrix which contains enzymes involved in respiration
What is the function of the mitochondria?
- Site of aerobic respiration where ATP is produced
What is the structure of a chloroplast?
- Small, flattened structure found in plant and algal cells
- Surrounded by a double membrane
- Membranes inside called thylakoid membranes, which stack up to form grana
- Grana linked together by lamellae (thin, flat pieces of thylakoid membrane)
What is the function of a chloroplast?
- The site where photosynthesis takes place
- Some part of photosynthesis take place in the grana, and other parts happen in the stroma
What is the structure of the Golgi apparatus?
- Stack of fluid-filled membranes that make up flattened sacs called cisternae
- Contains small hallow structures called vesicles
What is the function of the Golgi apparatus and the Golgi vesicles?
- Cisternae process and package lipids and proteins
- Vesicles store and transport lipids and proteins
- Produces lysosomes
- Adds carbohydrates to proteins to make glycoproteins
What is the structure of a lysosome?
- A round organelle surrounded by a membrane with no clear internal structure
- A type of Golgi vesicle
What is the function of a lysosome?
- Releases hydrolytic enzymes called lysozymes through a process called exocytosis
- Enzymes used to digest invading cells or break down worn out components of the cell
- Hydrolyses material ingested by phagocytic cells
What is the structure of a ribosome?
- Very small organelle
- No membrane
- Either attached to the RER or floats free in cytoplasm
- Made up of proteins and RNA
- 80S ribosome found in eukaryotic cells (around 25nm in diameter)
