Cells And Microscopy Flashcards
(27 cards)
What are prokaryotic cells?
Cells that have no nucleus and are single cellular. They are smaller and simpler
What are eukaryotic cells?
Cells that have a nucleus and can be single cellular or multicellular.
They are large and complex such as mamals
What is the cell unltrastructure?
The organelles and internal structures of cells
What are the two types of eukaryotic cells?
Animal
Plant
What does the plasma membrane do?
It is in prokaryotic cells and only plant cells and animal cells of eukaryotic cells.
It regulates the movement of substances and can act as sell signalling
What is the cell wall?
Found in plant cells and made of the carbohydrate cellulose.
This supports plants cells and stops them from bursting
What is the nucleus?
A large organelle surrounded my a nuclear envelope which contains many pores called nuclear pores. It contains chromatin and a structure called the nucleolus.
This controls the cells actions by controlling transcription of DNA and the pores allow substances to move between the nucleus and the cytoplasm.
The nucleolus makes ribosomes.
What is a lysosome?
A round organelles surrounded by a membrane with no clear internal structure. It contains digestive enzymes which are used to digest invading pathogens or to break down work components of cells.
Lysosomes keep the enzymes and cytoplasm separate
What are ribosomes?
A small organelle that either floats or is attached to the rough endoplasmic reticulum and is made up of proteins and RNA.
This is not surrounded by a membrane
This is the site where proteins are made.
What is the rough endoplasmic reticulum?
A system of enclosing a fluid filled space. The surface is covered with ribosomes
This folds, processes and packages that have been made in the ribosomes
What is the smooth endoplasmic reticulum?
A system of membranes enclosing a fluid filled space.
This synthesises and processes lipids
What is a vesicle?
A small fluid filled sac in the cytoplasm surrounded by a membrane.
These transport substances in and out of the cell and between organelles.
What is the golgi apparatus?
A group of fluid filled, membrane bound flattened sacs.
They process and package new proteins or lipids, and also make lysosomes.
What is the mitachondia?
An oval shaped organelle that is membrane bound. The inner membrane folds to form structures called the cristea. Inside is the matrix, which contains enzymes needed for respiration.
Mitachondria is the site of aerobic respiration
What is the chloroplast?
Small flattened structures surrounded by a double membrane. They have membranes inside called thylakoid membranes. These are stacked up to form grana, which are linked together by lamellae, which is thin flat pieces of thylakoid membrane.
Some photosynthesis occurs in the grana and some in the stroma, which is the thick fluid in chloroplast
This is the site of photosynthesis
What are centrioles?
Small hollow cylinders made of microtubules.
They are involved in cell division
What are cilia?
Small hair like structures found on the surface of of membranes.
In cross section they have 9 pairs microtubules on the outside and two in the inside.
Microtubules allow cilia to move and move substances along membranes.
What is the flagellum?
They are like cilia but longer. They contain 9 pairs of microtu ules on the outside and two on the inside. In prokaryotic cells they are made from flagella.
This allows flagellum to move
What proteins do the rough endoplasmic reticulum produce?
Proteins used outside of the cell
What is the cytoskeleton?
A network of proteins in the cytoplasm, made of microfilimants, microtubules, and intermediate fibres
What does the cytoskeleton do?
-Support cell organelles
-Strengthen the cell
-Transporting organelles
-Cause cell movement
How does the cytoskeleton work?
By constantly changing shape allowing it to respond to changes in the cell and carry out its functions
What are microtubules?
Globular proteins that form tiny protein cylinders that determine cell shape and act as tracks for organelle transport.
Spindle fibres are composed of microtubules
What are microfilaments?
Contractile fibres that formed from the protein actin. These are responsible for cell movement and contraction during cytokenisis.
