Eukaryotic Cells Flashcards
What is the function of the cell surface membrane?
- Partially permeable
- Formed from a phospholipid bilayer of phospholipids spanning a diameter of around 10nm
What are the features of the cell surface membrane?
- Surrounds cells + controls the exchange of materials between the internal cell environment and the external environment
What are the function of the cell wall?
- formed outside of cell membrane + gives structural support to the cell
- support is provided by the polysaccharide cellulose in plants + peptidoglycan in most bacterial cells
What are the features of the cell wall?
- found in plant cells, not animal
- narrow threads of cytoplasm (surrounded by cell membrane) called plasmodesmata connect the cytoplasm of neighbouring plant cells
What is the function of the nucleus?
- controls all cell activity
- where genetic code is stored, replicated and transcribed into RNA
- attached to the rough ER so mRNA can easily access ribosomes
What are the features of the nucleus?
-present in all eukaryotic cells (except red blood cells)
- relatively large + separated from cytoplasm by a double membrane (nuclear envelope) which contains pores
- nucleus contains chromatin (material from which chromosomes are made)
What are the features and the function of the nuclear pores?
-allows for small molecules to enter and leave the nucleus
- nuclear pores are important channels for the mRNA + ribosomes to travel out of the nucleus, as well as allowing enzymes (e.g. DNA polymerase) + signalling molecules to travel in.
What are the features and the function of nucleolus?
- composed of RNA and proteins
- usually one or more darkly stained regions can be observed - the sites of ribosome production
What are the features and the function of the nuclear envelope?
- double membrane which encompasses the nucleus and prevents damage. Protects the DNA
What is chromatin?
- A complex of DNA and histone proteins
- Sections of linear DNA tightly wound around proteins called histones
- contains the genetic code and controls the activity of the cell
What is the function of the mitochondria?
- the site of aerobic respiration within all eukaryotic cells
- surrounded by double membrane within the inner membrane folded to form cristae
What are the features of the mitochondria?
- matrix formed by cristae contains enzymes needed for aerobic respiration, producing ATP
- small circular pieces of DNA (mitochondrial DNA) and ribosomes are also found in the matrix (needed for replication)
What is the function of the chloroplasts?
- found
What are the features of the chloroplasts?
