Flashcards in Prokaryotes And Eukaryotes Deck (34):
What are the two major groups organisms, which depend on their cells?
Eukaryotes (the Protists, fungi, animals and plants) and the prokaryotes (the bacteria and archaea). Eukaryote means 'true nucleus' while prokaryote means 'before the nucleus'. However this is wrong in evolutionary terms; prokaryotes may well have arisen from simplified versions of early Eukaryotes!
what is a nucleoid?
A localised region of DNA.
What is the function of a ribosome?
The site of protein synthesis.
What is a peotidoglycan cell wall?
A matrix of polysaccharides linked by short polypeptide chains. Protects the cell, maintains it's shape and prevents excessive uptake of water.
What is the capsule?
A thick layer of polysaccharide outside the cell wall, it helps the cell adhere to surfaces.
What are pili?
Help the cell attach to surfaces and can be used to exchange plasmids with other bacteria.
What is the function of the flagellum?
Used for locomotion.
What are plasmids?
Additional rings of DNA in the cytoplasm - can be exchanged
What do prokaryote cells not have?
Do not have membranes bound by enzymes.
What do prokaryote cells have instead of membrane?
A circular chromosome suspended in the cytoplasm. They may also have smaller ring of DNA called plasmids.
what is the function of a single circular DNA molecule? Prokaryotes
Condenses to form a nucleotide.
What is the function of the cell membrane?
Controls exit and entry of materials
Folds to help localise metabolism
What is the function of pili?
-Exchange of plasmids
-Used to attach to surfaces
What is the function of the ribosome?
Protein synthesis, smaller site that eukaryotes
What is the function of the mucilaginious capusule?
Jelly like polysaccharide helps the cell adhere to surfaces.
What is the function of plasmodesmata? In plant cells
Present in cell wall. These are cytoplasmic links between neighbouring cells.
What is the central vacuole? Plant cells
Stores sugars, ions and pigments. It is important in maintain turgidity of the cell.
What is the function of chloroplasts? Plant
Carry out photosynthesis.
What is the function of the middle lamella? Plant
Composed of pectin which gives neighbouring cells together at their cell walls.
What is the function of the plant cell wall?
Made up of cellulose. Maintains the cells shape,as well as preventing excessive uptake of water.
What is the function of centrides? Animal
Formed in the centre some also known ad microtuble organising centre (MTOC).
What is function of the micro villi? Animal
Membranes extensions which increase the surface area for absorption.
What is the function of microbodies? Animal
Only have a single membrane around them and are produced by budding from the ER or the Golgi apparatus, lysosomes, which contain enzymes to digest and recycle parts of the cell.
What does cytosol have?
If plant cells are eukaryotes what does this mean?
They contain organelles bound by membranes.
What is cytosol?
Is the liquid part of the cytoplasm. It is organised by endomembranes which compartmentalise different parts of the metabolism. It has a cytoskeleton.
What is the function of the cytoskeleton?
It's is a network of protein fibres that extends throughout the cytoplasm in all eukaryotic cells. The cytoplasm is attached to membrane proteins and gives mechanical support to the cell. The act as a scaffolding to maintain the shape of the cell.
What is function of the mitochondria?
Are present in aerobic respiration. These have a double-layer of membranes with the inner layer folded to form cristae. They are the main energy source to the cell.
What is the nuclear membrane?
The membrane that surrounds the nucleus.
What is the nucleus?
A spherical body containing many organelles. The nucleus controls many of the cells functions, it contains DNA.
What are the chloroplasts?
They are the site of photosynthesis. They are an elongated organelle containing chlorophyll. They have their own DNA.
What is the endoplasmic reticulum?
The transport system for molecules needed for certain changes and specific destinations, instead of molecules that float freely in the cytoplasm.
What is the Golgi apparatus? Animal
A flattened, layered, sac-like organelle that looks like a stack of panels and is located near the nucleus. It produces the membranes that surround the lysosomes. The Golgi body packages proteins and carbohydrates into the membrane bound vesicles for "export" from the cell.