2.1.3 - Eukaryotic cells 1 Flashcards
define cytoplasm
jelly-like liquid that makes up the bulk of the cell and contains organelles
define nucleus
organelle containing the nucleic acids DNA and RNA as well as protein, surrounded by a nuclear envelope with pores
define protoplasm
the cytoplasm and nucleus combined
what is the Ultrastructure of the cell?
detailed organisation of the cell that can only be visible using an electron microscope
What surrounds the nucleus?
- nuclear envelope (double nuclear membrane with pores)
- chemicals pass in and out of the pores so that the nucleus can control events in the cytoplasm
what is the nuclear envelope made up of?
- nucleic acids (RNA and DNA) and proteins
define chromatin
granular combinations of DNA bonded to protein found in the nucleus when the cell is not actively dividing
define the nucleolus
extra dense area of almost pure DNA and protein found in the nucleus involved in the production of ribosomes and control of growth and cell division
list the three parts of the nucleus.
- nuclear envelope
- chromatin
- nucleolus
define mitochondria
rod-like structures with inner and outer membranes that are the site of aerobic respiration
what process occurs at mitochondria?
- aerobic respiration
- this is where simple molecules are oxidised to produce ATP
- this is then used to drive functions of the cell and the organism as a whole
How does the number of mitochondria link to the functions of that cell?
- cells that require very little energy (e.g white fat storage cells) will have less mitochondria
- cells with an energy demand (e.g muscle and liver cells) will have large numbers of mitochondria
Why do mitochondria have their own genetic material?
- so that when a cell divides, they can replicate themselves under the control of the nucleus
- it is called mitochondrial DNA and is part of the whole genome of the organism
define cristae
infoldings in the inner membrane of mitochondria which provide large surface area for aerobic respiration
define eubacteria
true bacteria (prokaryotic organisms)