1.2 cell structure and organisation Flashcards
Eukaryotic cells
have a nucleus and membrane bound organelles. Eukaryotic cells include plant and animal cells.
Nucleus
Contains DNA which codes for protein synthesis. ribosomes are formed here.
Nuclear pores
A double membrane with pores that allows mRNA and ribosomes out of the nucleus.
Nucleolus
sight of ribosome synthesis
Chromatin
Condenses before cell division to form chromosomes.
Nuclear envelope or double membrane
Separates the contents of the nucleus from the cytoplasm.
ribosomes
carries out the translation stage of protein synthesis. they are made of a large and a small subunit constructed from rRNA and protein.
Rough endoplasmic reticulum
Packaging and storing proteins. covered in ribosomes for protein synthesis; cisternae regular lines then transport the protein. Producing transport vesicles which merge to form the Golgi body.
Smooth endoplasmic reticulum
Produce, package and transport steroids and lipids. does not have ribosomes
mitochondria
Aerobic respiration occurs in the mitochondria and responsible for proudicng ATP. The inner membrane is folded into cristae. The cristae increase the surface area for protein synthesis.
golgi apparatus
stack of membrane bound. receives protein from ER and packages proteins for secretion from the cell. Modification of proteins e.g. by adding carbohydrate chains to form glycoproteins. forms lysosomes and digestive enzymes.
Chloroplasts
only found in plant cells which are double membrane. stacks of thylakoids in a granum. The thylakoid membranes contain chlorophyll, a pigment that traps light energy for photosynthesis.
Endoplasmic reticulum
These are a series of flattened sacs - double membraned cisternae leading on from the nuclear envelope.
Centrioles.
Only found in animal cells. They are 2 cylinders of microtubules that form the spindle fibre in cell division
lysosomes
single membrane with no specialised internal structure. formed in Golgi apparatus that contains digestive enzymes to break down cellular waste.
