Eukaryotic cells and organelles Flashcards
What are eukaryotic and prokaryotic cells?
Eu: make up eu. organisms, complex, e.g. all animal, plant, algae and fungi cells.
Pro: are prokaryotic organisms (single-celled organisms), simple, e.g. bacteria
What are the differences between pro. and eu. cells?
P:
no nucleus - loop of DNA
no proteins associated with DNA
no introns
Eu. :
DNA in nucleus, in linear chromosomes
Have proteins (histones)
However, mitochondria and chloroplasts have DNA that’s in a loop (circular) as well.
Structure of Eukaryotic cells:
- Label plant and animal cell
- Describe Algal and Fungal cells
Algal and Fungal Cells
1) Algal cells are a lot like plant cells - they have all the same organelles, including a cell wall and chloroplasts. They can be single celled.
2) Fungal cells are also a lot like plant cells, but with two key differences:
their cell walls are made of chitin, not cellulose.
they don’t have chloroplasts (because they don’t photosynthesise).
What are the extra organelles found in plant cells that aren’t found in animal cells?
- a cellulose cell wall with plasmodesmata (‘channels’ for exchanging substances with adjacent cells)
- a vacuole (compartment that contains cell sap),
- chloroplasts.
What might you see in plant cells that aren’t organelles?
You might also see starch grains in plant cells, although they’re not organelles. Plants use starch grains to store excess sugars.
Give some examples of fungi
e.g. mushrooms and yeast
What is the structure and function of:
the cell surface (plasma) membrane?
What is the structure and function of:
the nucleus
What is the structure and function of:
a mitochondrion
What is the structure and function of:
a chloroplast
What is the structure and function of:
the golgi apparatus
What is the structure and function of:
a golgi vesicle
What is the structure and function of:
a lysosome?
What is the structure and function of:
a ribosome?
What is the structure and function of:
the rough endoplasmic reticulum?
What is the structure and function of:
smooth endoplasmic reticulum?
What is the structure and function of:
the cell wall?
Where are specialised cells found?
In multicellular organisms
- cell wall
- capsule
- plasmids
- circular DNA
- flagellum
- cytoplasm
In a virus what is the function of:
The cell wall supports the cell and prevents it from changing shape. It’s made of a polymer called murein.
Murein is a glycoprotein (a protein with a carbohydrate attached).
In a virus what is the function of the capsule?
Some prokaryotes, e.g. bacteria, also have a capsule made up of secreted slime. It helps to protect bacteria from attack by cells of the immune system.
In a virus what is the function of: a plasmid
Plasmids are small loops of DNA that aren’t part of the main circular DNA molecule. Plasmids contain genes for things like antibiotic resistance, and can be passed between prokaryotes. Plasmids are not always present in prokaryotic cells. Some. prokaryotic cells have several.
In a virus what is the function of: the circular DNA
Unlike a eukaryotic cell, a prokaryotic cell doesn’t have a nucleus. Instead, the DNA floats free in the cytoplasm. It’s circular DNA, present as one long coiled-up strand. It’s not attached to any histone proteins
In a virus what is the function of: the flagellum
The flagellum (plural flagella) is a long, hair-like structure that rotates to make the prokaryotic cell move. Not all prokaryotes have a flagellum. Some have more than one.
In a virus what is the function of: the cytoplasm
The cytoplasm of a prokaryotic cell has no membrane-bound organelles (unlike a eukaryotic cell). It has ribosomes but they’re smaller than those in a eukaryotic cell.
In a virus what is the function of: the plasma membrane
It’s mainly made of lipids and proteins. It controls the
movement of substances into and out of the cell.
Describe viruses.
Viruses are Acellular
- They’re even smaller than bacteria-e.g. HIV is about 0.1 μm across.
- Unlike bacteria, viruses have no plasma membrane, no cytoplasm and no ribosomes.
- All viruses invade and reproduce inside the cells of other organisms. These cells are known as host cells.
