B1.1 - Cell Structures Flashcards
Sub cellular structure
Structures within the cell
Eukaryotic cells
Contain a nucleus - e.g. plant and animal cells
Prokaryotic cells
Do NOT have a nucleus - e.g. bacteria cellp
Cytoplasm
Jelly-like substance where all chemical reactions happen. Helps keep the cells alive
In all animal, plant, and bacteria cells
Cell membrane
A selective barrier that controls which substance pass in/out of the cell. Contains receptor molecules
In all animal, plant, and bacterial cells
Nucleus
Controls cella activity. Contains genetic material. Determines cell appearance and function. Contains instructions on how to make new cells/organisms
In only animal and plant cells
Mitochondria
Contains enzymes for cellular respiration .
In animal and plant cells
Chloroplasts
Contain green Chlorophyll which transfer light energy from sun to be used in photosynthesis. Only in the green parts of a plant
Only in plant cells
Vacuole
Full of cell sap (contains water and sugar). Keeps cell rigid and supports plant.
Only in plant cell
Cell wall
Surrounds cell. Made of tough fibre cellulose. Makes wall rigid. Supports cell
Only in plant cell
Plants make their own food. T/F?
True :)
Bacteria
Smallest living organisms. Unicellular (one cell only).
Rough Size of bacteria
1 μm (micrometer)
Flagellum (bac only)
Tail like structure allowing cell to move though liquid
Pili (bac only)
Tiny hair like structure ps enabling cell to attach to stuff. Transfer genetic material between bacteria
Slime capsule (bac only)
Located outside cell wall. Protects bacterium from drying out and from poisonous substances. Helps stick to smooth surfaces
Plasmid (bac only)
Circular piece of DNA. Stores extra genes.
Not needed for everyday life, but for times of stress
(E.g. this is where antibiotic resistance genes are found)
Microscope
Helps observe small structures in detail
How does light microscope work?
Passes light through object placed on clear stage - passed through two lenses which magnify it
Steps to set up light microscope
- Move stage lowest
- Select lowest objective lens
- Place slide on the stage and fix
- Raise stage to highest (do not touch lens)
- Slowly lower stage w/ course focus
- Turn fine focus until object in full focus
- For more detail, use high objective lens
Total magnification equation
Eyepiece lens x objective lens
Why stain cells?
Cells are colourless. Staining makes them easier to see
Methylene blue
Helps see NUCLEUS of ANIMAL CELL
Iodine
Helps see NUCLEUS of PLANT CELL
