Cell structure in eukaryotes Flashcards
What is the structure of the nucleus?
An organelle with a nuclear membrane with pores surrounding it with free chromatin and the nucleolus inside of it
What is the function of the nucleus?
Control of cell functions and make ribosomes and store chromatin (unravelled DNA)
What is the structure of the nucleolus?
An organelle inside the nucleus with RNA inside it
What is the function of the nucleolus?
produce rRNA to make ribosomes and hold RNA
What is the structure of the nuclear envelope?
A double membrane round the nucleus that has pores
What is the function of the nuclear envelope?
The pores allow large substances like mRNA to leave the nucleus. Substances like steroid hormones, many come from the cytoplasm through the pores
What is the structure of the rough endoplasmic reticulum?
A group of connected membranes with fluid filled cavities called cisternae that is continuous with the nuclear membrane. It has ribosomes on its surface
What is the function of the rough endoplasmic reticulum?
RER transport proteins through the cisternae to the rest of the cell,
It has a large surface area for ribosomes, which bind amino acids into proteins. Then they are sent to the Golgi apparatus
What is the structure of the smooth endoplasmic reticulum?
A group of connected membranes with fluid filled cavities called cisternae that are continuous with the nuclear membrane.
What is the function of the smooth endoplasmic reticulum?
These have enzymes that catalyse reactions to do with lipid metabolism like: making cholesterol, lipids, phospholipids and steroid hormones.
It is also used in absorbing, transporting and making lipids in the gut.
stores carbs and lipids
What is the structure of the Golgi apparatus?
This is a stack of membrane bound flattened sacs with secretory vesicles that bring materials in and out of the Golgi apparatus
What is the function of the Golgi apparatus?
This changes proteins by adding and/or changing its structure by adding carbs, lipids or folding it.
Vesicles then take the to be stored or to the plasma membrane to be used in the membrane or outside the cell
Cis-golgi face sorts and returns wrongly secreted proteins
Trans-golgi face secrete the vesicles that are filled with proteins to other places in the cell.
It makes lysosomes
It makes lipids
It replenishes the plasma membrane
What is the function of the mitochondria?
Site of ATP production in respiration
where are the mitochondria most commonly found
Site of ATP production in respiration
Abundant in cells where most of the metabolic activity takes place, such as neurones where neurotransmitter is synthesised and released
What is the structure of the chloroplast?
Large organelles, around 4-10 um
Had a double membrane with many flattened membranes called thylakoids
Each stack/pile of thylakoids is called a granum (grana)
The fluid filled matrix is called the stoma
Contains loops of DNA and starch grains
chlorophyll pigement present
What is the function of the chloroplast
Site of photosynthesis, where light is turned into ATP from CO2 and water. Water is split to provide the H+ ions in the granum and create ATP. In the second stage the hydrogen reduced the carbon dioxide to create glucose using ATP
What is the structure of a vacuole?
it is bound by a membrane(tonoplast) and filled with fluid.
What is the purpose of a vacuole?
It stores a solution of water and useful ions and molecules for the plant to use.
It is used to make the plant cell stable and turgid when it is full of water as it pushes against the cell wall.
when all cells are turgid the plant is better supported especially in the not wood plants
only plants have a large permanent vacuole
What is the structure of the lysosome?
A small bag filled with a single membrane
produced from the Golgi apparatus and is filled with strong hydrolytic enzymes.
It is more common in phagocytes as they will digest bacteria e.g macrophage and neutrophils.
What is the function of the sex flagella
they extend between cells in some tissues between special junctions enabling cell signalling
What is the structure of the cilia and flagella
They are projections from the cell covered with cell surface membrane and are made of centrioles which are made of microtubules. The cillia are 9:2 arrangement of microtubules
What is the purpose of the cilia and flagella?
The flagella are used in bacteria to move and are also used in the sperm cell to move.
Cilia are used to waft things away from the nose after being covered with mucus to remove bacteria front he body.
nearly all cells have a cilia to be a receptor for their environment
Which organelles are not membrane-bound?
ribosome, cell wall, centrioles and cytoskeleton
What is the purpose of the ribosome?
They are used to synthesise protein.
The ones floating around are for in cell and the ones on RER are for in cell use
