2.1 Cell Structure Flashcards
What is magnification
The number of times larger an image spears, compared to the size of the object
What is the formula for magnification
Magnification (M) = Image size (I) / actual/object size
What is resolution
The clarity of an image; the higher the resolution the clearer the image
What is the graticule?
It is a microscope tool thing used to measure cells
Why do we stain slides/specimen?
Stains are coloured chemicals that bind o molecules in or on the specimen, making the specimen easy to see.
What is differential staining?
Staining each cell structure differently
What is a micrograph?
An image taken from a microscope
What is the nucleus?
- The cell’s control centre, contains chromatin (made from DNA and proteins)
- Largest organelle in a cell
- Contains nucleolus
- Creates RNA and ribosomes
What is the nucleolus?
-The region at the centre off the nucleus that plays an important role in ribosome production
What is the mitochondria?
- The site of fat and sugar digestion in the cell
- Produces energy
- The inner membrane is folded to increase the surface area for releasing energy from sugars and fats
- The outer membrane is smooth and featureless
What is the rough endoplasmic reticulum?
- Folded membranes extending throughout the cell, studded with ribosomes
- Helps transport materials through cell
- Site of protein manufacture
What is the smooth endoplasmic reticulum?
-Synthesises and processes lipids
What is the golgi apparatus?
- Processes and packages new lipids and proteins
- Makes lysosomes
What is the lysosome?
-Contains digestive enzymes that aid in digestion and excretion of substances and worn-out organelles
What are ribosomes?
-The site where proteins are made
What is the centriole?
- Composed of 2 cylinders of tubules
- Essential to cell reproduction
What is the cytoskeleton?
-Internal framework of the cell, comprised of microfilaments and hollow microtubules
What is the cell wall?
- Is only found in plants
- Supports plant cells
What is the vacuole?
-A sac that stores and transports ingested materials, waste products and water
What is the chloroplast?
-The site where photosynthesis takes place
Some parts happen in the grana or the stroma(a thick fluid found in chloroplasts)
What is a eukaryote?
-A eukaryote is any organism consisting of one or more cells that contain DNA in a membrane-bound nucleus, separate from the cytoplasm.
What are examples of eukaryotes?
- Animals
- Plants
- Fungi
What do all eukaryotic cells contain?
-A large number of specialised membrane-bound organelles
What is a prokaryote?
A prokaryote is any organism (usually single-celled whose DNA is suspended freely in the cytoplasm.
What is the difference in the structure of prokaryotes and eukaryotes?
-Prokaryotes have simpler structures than eukaryotes, lacking organelles such as the nucleus, ER and golgi.
What do all prokaryotes have in common?
- No nucleus
- Very small (less than 2 micrometres in diameter)
- Cell wall made of peptidoglycan (not cellulose like in plants)
What are some examples of prokaryotic cells?
-Bacteria
What is the importance of the cytoskeleton?
- The microtubules and microfilaments support the cell’s organelles, keeping them in position
- Help to strengthen the cell and maintain it’s shape
- Responsible for movement of materials within the cell
- The proteins of the cytoskeleton cause the cell to move
HOW DOES PROTEIN PRODUCTION HAPPEN?
- Proteins are made at the ribosomes (ribosomes sometimes at RER)
- Folded+processed in the RER
- Transported from the ER to the golgi apparatus in vesicles
- At the golgi apparatus, proteins may undergo further processing
- Proteins enter more vesicles to be transported around the cell
What are vesicles?
-Transports substances in and out of the cell + between organelles
What does the plasma (cell surface) membrane do
- Regulates movement of substances into and out of the cell
- Has receptor molecules on it which allow it to respond to chemicals like hormones
Magnification formula
Image size/ / Object size
