Chapter 1: Cells🧫 Flashcards
Light microscope magnification and function
1000x, for coloured images of main structures
Electron microscope magnification and function
200 000x, black and white images of smaller structures
Protoplasm
Jelly-like substance where most cell activities are carried out
Consists of cell surface membrane, cytoplasm and nucleus
Cell surface membrane
- Surrounds cytoplasm
- Made of lipids and proteins
- PPM: controls movement of substances
Cell wall
- encloses plant cell
- made of cellulose
- protects cell from injury + fixed shape
- f fully permeable
Cytoplasm
- most cell activities happen here
- mainly consists of water
Organelles
Membrane bound cellular structure that performs a specific job within a cell
Nucleus description
- surrounded by nuclear membrane
- consists of nucleoplasm
- contains genetic info in the form of chromosomes
- may contain nucleoli and chromatin
Nucleus function
- controls cell activities: cell growth, repair of work out parts and protein synthesis
- essential for cell division
Chromosomes
- Long thread-like structures (48 in human cell)
- made up of proteins and deoxyribonucleic acid (DNA: contains hereditary info)
- chromatin threads coil and condense into thick rod-like structures to become chromosomes when cell is dividing
Rough endoplasmic reticulum (RER) appearance
- network of flattened spaces lined with membrane
- appears rough due to attached ribosomes
- outer surface of RER is continuous with the nuclear membrane
RER function
Transports proteins to golgi apparatus for secretion out of cell
Ribosomes (attached)
Attached to RER
Synthesises proteins that are transported out of cell
Ribosomes (free)
Free in cytoplasm
Synthesises proteins used in cell
Smooth endoplasmic reticulum (SER) appearance
No attached ribosomes
More tubular than RER
Connected to RER
Smooth endoplasmic reticulum (SER) function
Synthesises substances: data and steroids
Concerts harmful substances to harmless ones (detoxification)
Golgi Body / Golgi apparatus appearance
Stack of flattened spaces surrounded by membranes
Golgi body / Golgi apparatus function
Stores and chemically modified substances made by ribosomes
Stores and packages these substances in vesicles for secretion out of cell
Vesicle appearance
Tiny spherical spaces enclosed by membrane
Vesicle function
Fuses with one side of Golgi body and pinches off the opposite side
Vesicle process
- Vesicles with substances from RER pinches off from RER
- Vesicles fuse with Golgi body
- Substances released into Golgi apparatus are modified and packaged
- Secretory vesicles with substances pinch off Golgi body and move towards cell surface membrane
- Secretory vesicles fuse with cell surface membrane and release substances into exterior of the cell
Mitochondria
Site of aerobic respiration: food substances are broken down to release energy (oxidise glucose to release energy for cell activities like growth and respiration)
Chloroplasts
Oval structures
Contain chlorophyll which absorbs light energy to carry out photosynthesis
Vacuoles
Fluid-filled space enclosed by a ppm (tonoplast in plants)
Stores substances within a cell
Plant: large central vacuole containing cell sap
Animal: many small vacuoles containing water and food substances (exist temporarily)
