Cell Organelles 1 Flashcards
List the five organelles that will be studied in great detail.
Cytosol
Cytoplasm
Nucleus
Endoplasmic reticulum
Golgi apparatus
How are many of the cell organelles held in their correct locations in the cell?
Many of the organelles are held in their relative locations in the cell by attachment to the cytoskeleton, especially to microtubules
What is the cytoskeleton?
2
A network of protein filaments and tubules that stretches through the cell
It allows for the movement of organelles around the cell
What do the cytoskeletal filaments do?
They provide tracks for moving the organelles around and for directing traffic of vesicles between them
What drives the movements of organelles through cytoskeletal filaments?
These movements are driven by motor proteins that use energy of ATP hydrolysis to propel the organelles and vesicles along the filaments
List the organelles of a typical animal cell.
9
Cytoplasm Cytosol Nucleus Endoplasmic reticulum Golgi apparatus Mitochondrion Vacuole Lysosome Peroxisome
What is the cytosol?
The concentrated aqueous gel (cytoplasm - the organelles)
Write a note on the cytosol.
2
Its the site of many chemical reactions e.g. protein manufacture (ribosomes), breakdown of nutrient molecules
Its a water based gel containing small and large molecules
What is the cytoplasm?
2
Cytosol + membrane bounded organelles except for the nucleus
i.e. contents of cell within plasma membrane but outside the nucleus
Write a note on the cytoplasm.
2
It’s in constant motion
The cytoskeleton moves organelles around the cell through the cytoplasm
What three things make up the cytoskeleton?
Actin filaments
Microtubules
Intermediate filaments
Write a note on the nucleus.
3
The most prominent cell organelle
5 um in diameter
Contains the genetic material which is made up of nucleic acids (DNA and RNA)
Other than the nucleus, where is DNA found?
Mitochondria
Chloroplasts
List the four parts of the nucleus.
Nucleolus
Nuclear membrane
Chromatin
Nucleopore
Describe the structure of the nucleus.
5
Lipid bilayer encloses the nucleus to form the nuclear envelope
Envelope has perforations - nuclear pores
Pore complex (protein structure) lines pores and regulates entry and exit of particles
Nuclear lamina lines the nuclear side of the envelope
Nucleolus is found in non-dividing nucleus
What type of membrane does the nucleus have?
A double membrane made of a lipid bilayer
What are the perforations in the nuclear envelope called?
Nuclear pores
What lines the nuclear pores?
The pore complex
What is the pore complex?
A protein structure
What does the pore complex do?
It regulates the entry and exit of particles from the nucleus
What lines the nuclear side of the nuclear envelope?
The nuclear lamina
What is the nuclear lamina?
An array of protein filaments with anchor-sites for chromatin
What can only be found in non-dividing nucleus?
Nucleolus
Name the two parts of the nuclear membrane.
Outer membrane
Inner membrane
What is the function of the nuclear envelope?
It encloses the nucleus to separate contents from cytoplasm
List the order of layers of the nucleus.
6
Outer membrane Perinuclear space Inner membrane Nuclear lamina Nucleoplasm Nucleolus
What exactly are nuclear pores?
Protein-lined channels in the nuclear envelope
How do nuclear pores appear?
They look like perforations on the surface of the nucleus
What is the nucleolus made up of?
Protein
Ribosomal DNA (rDNA)
Write a note on the nucleolus.
2
No membrane
It’s the site of RNA transcription, RNA processing, ribosome assembly
What happens in the nucleolus?
RNA transcription
RNA processing
ribosome assembly