CELL BIOLOGY Flashcards
what are Cell requirements for life
Energy source
Light or chemical
Matter
Gases such as CO2 and O2
Simple nutrients
Monosaccharides, disaccharides, polysaccharides
Amino acids, fatty acids, glycerol, nucleic acids, ions and H2O
Removal of wastes
CO2, O2, urea, ammonia, uric acid, H2O, ions, metabolic heat
what is Field of View
The maximum area visible when looking through themicroscopeeyepiece (eyepieceFOV), usually quoted as a diameter measurement.
what is Magnification
Magnification refers to the number of times larger an object appears compared to its actual size.
what is Resolution
Resolution is the ability to distinguish between close together but separate object
learn how to calculate magnetism- look in notebook
If you increase the magnification, how will it affect the field of view?
Increase field of view decrease magnification
Decrease field of view increase magnification
learn all the calculations and everything from the powerpoint
learn parts of a microscope from powerpoint
Prokaryotic cells explain
Unicellular organisms Simple cell structure Small: 0.1–5.0 µm in diameter Have a cell membrane and outer cell wall Bacteria also have a capsule outside the cell wall Many have a flagella for movement
Prokaryotic cells (cont.)
Contains some organelles
But unlike eukaryotes, these organelles are not bound by a membrane
E.g. no proper nucleus, but still has DNA
Genetic material is mostly in a single circular DNA chromosome called a genophore.
There are also other smaller rings of DNA rings called plasmids.
Eukaryotic cells
Can be multicellular or unicellular
More complex cell structure
Large: 10-100 µm in diameter
Have a cell membrane and sometimes a cell wall
Eukaryotic cells
Cell compartmentalisation
Organelles bound by internal membranes
E.g. nucleus, mitochondria, chroloplast
Cell compartmentalisation
Multiple membranes mean that organelles can have a different internal composition from the surrounding cytosol and other organelles.
Allows processes that require different environments to occur at the same time, in the same cell
Allows relevant enzymes and reactants to be close together in high concentration and under the right conditions high efficiency
what is cell membrane, nucleus, cytoplasm
one of the membranes of the cytoplasm which keeps it all together
-helps control what goes in and out of the cell
nucleus
-contains chromosomes where inherited info is stored
cytoplasm
-lots of membranes made from proteins and fats
Purpose of the cell membrane
Provides a boundary between the extracellular and intercellular environment
Controls movement between the extracellular space (fluid) and the intracellular space (cytosol)
Phospholipid
Hydro: water
Philic: loving
Phobic: fearing
Phosphate end is polar and therefore hydrophilic (water-loving)
Fatty-acid side is non-polar and therefore hydrophobic (water-hating) – but is ok with non-polar liquids, e.g. oil.
Cholesterol
Stabilises the membrane
At high temps, stops membrane from being too fluid by restricting phospholipid movement
At low temps, stops membrane from being too solid by restricting tight packing of phospholipids
Glycoproteins
A type of molecule made up of a carbohydrate (sugar) linked to a protein that protrudes on the outer surface of the membrane.
Play important roles in cell adhesion and recognition.
Protein channels
Proteins are embedded all throughout the cell membrane and play a wide variety of roles.
One of the most important uses are as transport channels.
Permeability
Cell membranes are said to be semi-permeable ◦ They allow solvent molecules to pass through, but prevent some of the solute molecules from doing so. ◦ Also known as selectively permeable.
What can pass through a
phospholipid bilayer?
Only molecules that are “accepted” in the inner hydrophobic (oily) region! - Small, uncharged molecules - Lipid-soluble molecule