week 1 Flashcards
RER - Rough endoplasmic reticulum SER - Smooth endoplasmic reticulum GA - Golgi Apparatus E - eukaryotic P - prokaryotic (40 cards)
what are the properties of the main molecules of life?
- Amino Acids polymerise into Proteins
- Purines and Pyrimidines polymerise into Polynucleotides
- Polynucleotides can directly guide the formation of exact copies of their own sequence (base pairing of DNA)
what did early earth consist of?
- Molten Surface?
- Atmosphere ammonia or methane?
- Little free Oxygen
- No Ozone
- Generally agreed –violent conditions, volcanic eruptions, lightning, storms….
- Great conditions for producing simple carbon-based (organic) molecules
what happens if you mix gases sucg as CO2, CH3, NH3 and Hydrogen in water?
they react to form small organic molecules Purines, Pyrimidines,Sugars, Amino Acids
what is the function of a plasma membrane?
- Every cell is surrounded by a plasma membrane
- Maintain homeostasis
- Selectively permeable
- Important in communicating without side environment
- Aids in binding and adhering
what does cell theory state?
– Cells are the fundamental units of life.
– All organisms are composed of cells.
– All cells come from pre-existing cells.
who was Robert Hooke and what did he discover?
The cell was first described by Robert Hooke
He remarked that they looked strangely similar to cellula or small rooms whichmonks inhabited, thus deriving the name.
However what Hooke actually saw were the dead cell walls of plant cells (cork) as they appeared under the microscope
who was Anton Van Leeuwenhoek and what did he discover?
The first man to witness a live cell under a microscope was Anton Van Leeuwenhoek, who in 1674 described the algae Spirogyra.
Leeuwenhoek probably also saw bacteria when looking at the algae but didn’t describe them at the time
how is a plasma membrane structured?
The plasma membrane is a lipid bilayer with proteins and other molecules embedded in it. Some archaea have a lipid monolayer.
what is the size of the smallest object a person can see?
- Smallest object a person can see is about 0.2 mm (200 μm) in size
.* Objects must be about this distance apart for them to be distinguished from one another (resolution).
- Most cells smaller than 200 μm in size
what is the resolution of a Light Microscope?
Resolution 0.2 μm (About 1000 times that of the human eye
what is the famous quote from Matthias Jakob Schleiden? (Cell Theory)
“All plants are made up of cells”
what is the famous quote from Rudolf Virchow? (Cell Theory)
“Cells come from cells”
what is the famous quote from Theodor Schwann? (Cell Theory)
“The cause of nutrition and growth resides not in the organism as a whole but in the elementary parts – the cells.”
who came first out of Scheiden, Virchow and Schwann?
the order is as follows:
Schleiden - “all plants are made up of cells”
Virchow - “Cells come from Cells”
Schwann - “The cause of nutrition and growth resides not in the organism as a whole but in the elementary parts – the cells.”
what is the resolution of a electron microscope?
The resolution 0.2 nm.
(About 1,000,000 times greaterthan the human eye)
what is cell size limited by and how?
Cell size is limited by the surface area-to-volume ratio.
what is meant by surface in relation to cell size?
The surface of a cell is the area that interfaces with the cell’s environment.
what is meant by cell volume?
The volume of a cell is a measure of the space inside a cell.
what is meant by surface-area: volume ratio?
- Surface - area: volume ratio is defined as the surface area divided by the volume.
- For any given shape, increasing volume decreases the surface -area: volume ratio
why do we use the surface-area: volume ratio?
- The volume of a cell determines how much chemical activity it can carry out per unit of time.
- The surface area of the cell determines the amount of a substance it can take in from the external environment and how much waste itcan release into the environment.
what is unique about the structure of Prokaryotic cells when compared to Eukaryotic cells?
they have no nucleus or other membrane-bound compartments. They lack distinct organelles
what is unique about the structure of Eukaryotic Cells in comparison to Prokaryotic cells?
Eukaryotic Cells have a membrane-enclosed nucleus and other membrane-enclosed compartments and organelles
what are the shared features of prokaryotic and eukaryotic cells?
Cytoplasm
Ribosomes
Nucleoid
Plasma
Membrane
Do prokaryotic cells have cell walls?
- Some prokaryotic cells have Cell Walls
- Located outside plasma membrane
- Maintains shape of cell
- Cell wall of most bacteria (Not Archaea) contains peptidoglycan (sugars and amino acids)
*In some bacteria (Gram –ve) an outer layer of lipopolysaccharide (lipid and pilysaccharide) and protein encloses the peptidoglycan layer