1.2- Cell Structure and Organisation Flashcards
What are eukaryotic cells?
they have a nucleus and membrane bound organelles
What are examples of eukaryotic cells?
animal and plant cells
What are animal and plant cells known as?
eukaryotic cells
What is the nucleus?
its a membrane bound structure that contains the cells genetic information and controls the cells activities
What are nuclear pores?
enable molecules to enter and leave the nucleus, also transport nucleotides
How many parts is there to the nucleus?
4
What are the parts of the nucleus?
nuclear envelope
nucleolus
nucleoplasm
nuclear pores
What is the nuclear envelope?
a double membrane which contains an outer and inner layer that separates the nucleus from the cytoplasm
What is the nucleolus?
small spherical body that manufactures RNA, which is needed to make ribosomes
What is the nucleoplasm?
cytoplasm like material in the inner of the nucleus, where the cell’s DNA is located in the form of chromatin
What is mitochondria?
it has a double membrane structure and is the site of aerobic respiration within the cell
the inner membrane is folded inwards to form extensions called cristae which provide a larger surface surface area for ATP synthesis to occur
What is rough endoplasmic reticulum?
series of flattened sacs enclosed by a membrane with ribosomes on the surface
It folds and processes proteins made on the ribosomes
What is smooth endoplasmic reticulum?
a system of membrane bound sacs and is involved with the synthesis and transport of lipids
What are ribosomes?
small organelles found either free in the cytoplasm or attached to the rough ER
they are the site of protein synthesis
they read RNA to make proteins
What is Golgi body?
series of fluid filled, flattened & curved sacs with vesicles surrounding the edges
it processes and packages proteins and lipids
also produces lysosomes and digestive enzymes
What are the steps of the Golgi body functioning?
- vesicles containing proteins formed by the rough ER fuse at one end of the Golgi sacs
- the protein is modified inside the Golgi sacs
- the modified protein then travels to the cell’s outer plasma membrane where the protein is released to the outside of the cell
this process of releasing the protein is called exocytosis
What are lysosomes?
a vesicle bound by a single membrane which contains digestive enzymes which break down worn out organelles or cells
What are centrioles?
hollow cylinders containing a ring of microtubules arranged at right angles to each other
they form the spindle during cell division
What are chloroplast?
oval-shaped and have a double membrane, the inner and outer
it contains photosynthetic pigments which trap light energy for photosynthesis
the space within the inner membrane is called the stroma
What is a permanent vacuole?
it contains cell sap and stores solutes like glucose, surrounded by a tonoplast membrane
What are prokaryotic cells?
they don’t have any membrane bound organelles and the DNA is suspended freely in the cell
What are the cells walls made out of prokaryotes?
murein
What are the cells walls made out of eukaryotes?
cellulose