CP 2 The Cell Flashcards
What are the general characteristics of a living organism
- Exhibits growth and development into highly ordered forms
- Made of one or more cell
- Building instructions stored in DNA
- Maintain homeostasis
- Requires energy (ATP)
- Reproduce on their own
- Evolve
- Die
How does Life exhibits emergent properties
Individual molecules come together to become increasingly organized and complex
what is Central dogma of molecular biology
- Life based on DNA->RNA->Protein
- DNA can store tremendous amnts of info
- DNA storage could last over 1000 years
Are viruses a form of life?
- No, needs DNA,
- Not universally accepted though
TF Water is the solvent of life and why?
T
- Dissolves more molecs than any other solvent
- Dissolves polar and charged molecs
What r the 4 types of macromolecs
- Carbs
- Lipids
-proteins - Nucleic acids
what are carbs
polymers of sugars
are lipids polymers ?
No, don’t see alternating units of polymers
what are proteins
polymer of amino acids
what are nucleic acids
polymers of nucleotides
How r polymers formed
- Several monomers go thru polymerization (Using dehydration synthesis) to form polymers
what is depolarization
polymers broken down using hydrolysis
what r the 4 structures of amino acids
Primary structure - amino acid chain
Secondary structure – ex) α-helix, β-sheet
tetrinary structure - folding
Quatrinary structure – assembling with other proteins into a complex
what r 2 polymers of carbohydrates
Amylose
Cellulose
Why are cells so small
- Surface are needs to be sufficient for transportation of molecs thru membrane
- Lrger volumes req more surface area+structural support
- If the SA is not large enough to meet the demands of cell V, the cell will stop growing
- High SA, low vol—Low SA, High Vol
What are the 3 characteristics of Microscopy
- Resolution: distinguish details of a specimen or sample
- Magnification: Observed size/actual size(higher magnification increases resolution
- Contrast: Higher contrast give more details (sharpness)
what is resolution
ability to distinguish 2 objects as separate
what is Magnification
Observed size/actual size(higher magnification increases resolution
what is Contrast
Higher contrast give more details (sharpness)
how does a light microscope work
- Uses lenses to bend light up to 100-fold
- Used to view specimens in natural colour
- Uses chemical dyes and fluorescent labelling to increase contrast
what are the 4 types of light microscope
- Brightfield
- Darkfield
- Phase-contrast
- Differential Interference Contrast (DIC)
how does a darkfield microscope work
- Provides dark background
- Light is directed at the specimen at an angle, not directly at the specimen
Provides better contrast
How does a phase contrast microscope work
- Microscope captures phase changes in the light
Higher detailed images
How does a DIC microscope work
- Similar to phase contrast
Gives a 3D type look
What do both Prokaryotic and Eukaryotic have
- Plasma membrane
- Cytoplasm
- Chromosome
- Ribosome
- DNA
What is an electron Microscope+how is it better
-Uses electrons to illuminate specimen
-Provides greater magnifications and resolutions
What is a Transmission Electron Microscope(TEM)
- Uses very thin tissue slices
- Chemically fixed and dehydrated
- Stained with heavy metals
- Cannot see living cells
What is a scanning election microscope
(SEM)
- Scatter electrons over surface to get depth+3D image
- Also uses chemicals+ dehydrated + heavy metals
what is Fluorescence Light microscopy
- Uses high intensity shorter wavelength light to hit specimen
- Specimen then emits low wavelength fluorescence
- Also uses fluorescence(dyes, proteins, pigments(from specimen))
what is Confocal Fluorescence microscopes
- Increases contrast by capturing very thin slices of the specimen
Does this by passing light thru a tiny pinhole
what is the endomembrane system
- Divides eukaryotic cells into functional structural compartments
- Components are either continuous or connected via transfer by vesicles
what does the endomembrane system consist of
- Nuclear envelope
- ER
- Golgi apparatus
- Lysosomes
- Vacuoles
- Plasma membrane
what is a ribosome
- Composed of 2 subunits
- Site of protein synthesis
What is the endoplasmic reticulum
- Continuous of nuclear envelope
2 types (rough and smooth) - Rough ER
○ Ribosomes attached
○ Synthesizes proteins - Smooth ER
○ No Ribosome attached
○ Synthesize lipids, phospholipids and steroids, not proteins
○ Regulates carbohydrate metabolism in some cells
○ Stores calcium
○ Detoxifies drugs and toxins
what is the ER Lumen
- Further modification, polishing and folding of proteins occur here after they have been made by the ER
- Then they are transferred to plasma memb. by vesicles
what is the Golgi apparatus
- Shipping and receiving centre
- Consists of flattened membranous sac
- Modifies product of ER-chemically modifies proteins
- Manufactures macromolecs
○ Eg) glycolipids