1.2 ultra structure of cells Flashcards
1
Q
what are Prokaryotes and what is their structure?
A
- bacteria cells
- Prokaryotes have a cell wall and plasma membrane and cells filled with cytoplasm
- Prokaryotes have a nucleoid region, not a neuclous.
- Prokaryotes contain 70S ribosomes, which are smaller than ribosomes found in eukaryotes.
- Prokaryotic DNA is a naked loop
2
Q
how to draw a prokaryote?
A
- should show the cell wall, pili, flagella, and plasma membrane enclosing cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA
- flagellum length should be drawn twice as long as the prokaryote.
- The pili are drawn much shorter
3
Q
what is the process of binary fission?
A
- Prokaryotic cells divide by binary fission.
- asexual reproduction.
- starts with DNA replication.
- The DNA is then separated and moves to either side of the cell.
- The cell then splits (cytokinesis which means ‘cell splitting’) into two new cells.
- The new cells are daughter cells.
- The two cells are genetically identical
4
Q
what are eukaryotes?
A
- more complex internal structure than prokaryotes
- have internal compartments to separate parts of the cell that perform different functions
- cytoplasm contains many different organelles that are surrounded by either a single or double membrane, thus separating them into separate compartments
- Compartmentalisation ensures substrates and enzymes are more
concentrated, minimise damage to cell by storing certain enzymes or chemicals, optimal conditions (i.e. pH), and contents in organelles can be moved within the cell easily. - Eukaryotic DNA are associated with proteins and form linear chromosomes that is enclosed within the nucleus
5
Q
drawing an animal cell.
A
- Drawings of eukaryotic cells should show a plasma membrane enclosing cytoplasm that contain 80S ribosomes and a nucleus, mitochondria and other membrane-bound organelles in the cytoplasm.
6
Q
drawing a Plant cell.
A
- cell wall
- Drawings of eukaryotic cells should show a plasma membrane enclosing cytoplasm that contain 80S ribosomes and a nucleus, mitochondria and other membrane-bound organelles in the cytoplasm.
7
Q
what do Exocrine gland cells of the pancreas do?
A
- secrete digestive enzymes into a duct that carries the enzymes to the small intestine to digest foods.
- Enzymes are proteins, so the exocrine gland cells have organelles responsible for synthesising large quantities, processing and transporting proteins
8
Q
what does the plasma membrane do?
A
- separates each cell, and controls the entry and exit of materials such as
proteins (enzymes).
9
Q
what does the Mitochondrion do?
A
- site of cellular respiration to
provide ATP required for protein synthesis. - Mitochondrion will be spherical or ovoid in shape with a double membrane
10
Q
what does the Golgi apparatus do?
A
- Package and transports proteins (enzymes).
11
Q
what does the Nucleus do?
A
- controls cellular activities
12
Q
what does the Rough endoplasmic reticulum (rER) do?
A
- synthesis of proteins (enzymes).
- The rER should be adjacent to the nucleus and characterised by ribosomes on the surface.
13
Q
what do Vesicles do?
A
- transport of proteins (enzymes) around the cell or towards the plasma membrane.
14
Q
what do lysosomes do?
A
-contains enzymes that break down cells or cell products.
- Lysosomes are generally unique to animal cells.
- Usually will have a large concentration of proteins and will have dense staining for an electron micrograph.
15
Q
how does photosynthesis in The palisade mesophyll cells happen?
A
- Palisade mesophyll cells are generally cylindrical.
- Cell wall: provides structure and support for the cell.
- Plasma membrane: To separate each cell and controls entry and exit of materials such as glucose (product of photosynthesis).
- Mitochondrion: site of cellular respiration where it provides ATP for necessary photosynthesis.
- Chloroplast: site of photosynthesis.
- Vacuole: Storage of cell products.
- Nucleus: controls cell activities.
