Cells To Systems - Organelles
Organelles
Eukaryotic Are Divided Into Compartments:
Organelles - Cell is divided into different components
Discrete structures of a eukaryotic cell
Each organelle carries out specialised functions
Has an enclosed membrane (mostly)
Distributed throughout the cytoplasm on the cells
Nucleus:
Most prominent organelle in the cell
Nucleus
Big (3 - 10 µm)
Contains characteristics of eukaryotic Nucleolus
Contains the genome within nucleoplasm
Has chromosomes and proteins
Site of DNA storage
Site of DNA and RNA synthesis
Inside the nucleus is the nucleolus and cytoplasm
Chromosomes:
Not always visible
Undergo mitosis and start to condense
They become visible as a cell is about to divide
Nucleolus:
Sub-nuclear Structure - Consists of either
Is a sub-nuclear structure
proteins; proteins & RNA; proteins & DNA;
Site of ribosome production They will come together, combine and proteins, DNA & RNA
rRNA will be synthesised be exported out of the nucleus
It is not membrane bound rRNA - Ribosome RNA
The sizes vary depending on the number of ribosomes produced (more ribosomes = bigger)
Nuclear Envelope:
It is a double lipid bilayer with pores where inner and outer membranes connect
The envelope is penetrated by pores (which are symmetrical)
The pores act as gates to allow RNA, proteins and other molecules to move
appropriately
Provides Quality Control - Proteins will determine what will go inside and
outside e.g. only mature mRNA (messenger RNA) leaves the nucleus
Nuclear Support:
Supported mechanically by networks of intermediate filaments e.g. cytoskeleton both on the outside
and inside the nuclear envelope e.g. nuclear lamina (located inside)
Has a fibrous network
Endoplasmic Reticulum:
1
Organelles
Eukaryotic Are Divided Into Compartments:
Organelles - Cell is divided into different components
Discrete structures of a eukaryotic cell
Each organelle carries out specialised functions
Has an enclosed membrane (mostly)
Distributed throughout the cytoplasm on the cells
Nucleus:
Most prominent organelle in the cell
Nucleus
Big (3 - 10 µm)
Contains characteristics of eukaryotic Nucleolus
Contains the genome within nucleoplasm
Has chromosomes and proteins
Site of DNA storage
Site of DNA and RNA synthesis
Inside the nucleus is the nucleolus and cytoplasm
Chromosomes:
Not always visible
Undergo mitosis and start to condense
They become visible as a cell is about to divide
Nucleolus:
Sub-nuclear Structure - Consists of either
Is a sub-nuclear structure
proteins; proteins & RNA; proteins & DNA;
Site of ribosome production They will come together, combine and proteins, DNA & RNA
rRNA will be synthesised be exported out of the nucleus
It is not membrane bound rRNA - Ribosome RNA
The sizes vary depending on the number of ribosomes produced (more ribosomes = bigger)
Nuclear Envelope:
It is a double lipid bilayer with pores where inner and outer membranes connect
The envelope is penetrated by pores (which are symmetrical)
The pores act as gates to allow RNA, proteins and other molecules to move
appropriately
Provides Quality Control - Proteins will determine what will go inside and
outside e.g. only mature mRNA (messenger RNA) leaves the nucleus
Nuclear Support:
Supported mechanically by networks of intermediate filaments e.g. cytoskeleton both on the outside
and inside the nuclear envelope e.g. nuclear lamina (located inside)
Has a fibrous network
Endoplasmic Reticulum:
1
