3.4 Eukaryotic cell structure Flashcards
Define Metabolism
The sum of all chemical reactions taking place in an organism
Define the nuclear envelope
- a double membrane that surrounds the nucleus
- often has ribosomes on its surface
-controls the entry and exit of materials in and out of the nucleus
-contains reactions happening inside
What do nuclear pores do?
allow the passage of large molecules out of the nucleus
What makes up he bulk of the nucleus?
the nucleoplasm
What do chromosomes consist of?
protein bound- linear DNA
What is the purpose of the nucleolus?
it manufactures ribosomal RNA and assembles ribosomes
What are the functions of the nucleus?
-act as a control centre of the cell through the production of mRNA and tRNA and hence protein synthesis.
-retain the genetic material of the cell in the form of DNA and chromosomes
-manufacture ribosomal RNA and ribosomes
What surrounds the mitochondrion?
A double membrane that controls the entry and exit of material
Define the Cristae
extensions of the inner membrane in which providing a. large surface area for the attachment of enzymes and other proteins involved in respiration
?What does the ‘matrix’ of the mitochondrion contain?
-proteins, lipids, ribosomes and DNA
-enzymes used in respiration
Why are the number and size of the mitochondria high?
They are responsible for the production of the energy carrier molecule ATP
Give some examples of metabolically active cells
-muscle cells
-epithelial cells
Define the chloroplast envelope
double plasma membrane that surrounds the organelle- highly selective in what it allows to leave and enter the chloroplast
Where in the Chloroplasts would you find chlorophyll?
In the thylakoids- When stacked these are called the grana
How are chloroplast adapted to their function?
-The granal membranes provide a large surface area for the attachment of chlorophyll
-the fluid of the storm possesses all the enzymes needed to make sugars in the second stage of photosynthesis
-chloroplasts contain both DNA and ribosomes so they can quickly and easily manufacture some of the proteins needed for photosynthesis
