Microscopy Skills Flashcards
Evidence of Endosymbiotic Theory
Mitochondria and Chloroplast both:
Have 70s ribosomes
Double membrane
Their own DNA
Can divide by binary fission
Are the same size as bacteria
Endosymbiotic Theory for Mitochondria and Chloroplast
Mitochondria: The mitochondria got engulfed by a larger eukaryotic cell. The cell provided it with food and protection while the mitochondria converted the food into ATP for the cell
Chloroplast: The chloroplast got engulfed by a larger eukaryotic cell. The cell provided it protection while the chloroplast provided the cell with organic matter
Centrosomes
Cell movement and Cell division
Evidence that Cells only Come From Pre-Existing Cells
Cells are complex structures
The origin of all cells can be traced back to the first cell
Genetic code is universal
Ribosome
Small spherical structure that can either be attached to the RER or free in the cytoplasm
When free in the cytoplasm, they make proteins for the cell
When attached to the RER, they make proteins to export from the cell
Endoplasmic Reticulum
RER: A network of membranes that have ribosomes attached to its surface
SER: A network of smaller membranes with no ribosomes
RER synthesizes proteins and transports them
SER produces lipids such as membrane phospholipids and sex cells
Differentiation
The process where a less specialized cell becomes a more specialized cell
Advantages of Compartmentalization Part 2
Allows for specialized control of major DNA functions
More complex proteins and RNA products are formed separately
The nuclear envelope allows gene expression regulated by eukaryote only mechanisms
Nucleus
The region that contains chromosomes which is responsible for controlling the cell
Advantage and Disadvantage of Large SA:V Ratio
Shorter diffusion pathway, so molecules don’t have to travel far
High-rate heat gain and heat loss, so they require more nutrients
Evidence for LUCA
All organisms use DNA as genetic material
Same structure of double helix
Same 20 amino acids
Same mechanism for protein synthesis
Organelles that have No Membrane, Single Membrane, or Double Membrane
No:
Ribosome, Centriole, Microtubule
Single:
Vesicle, RER, SER, Golgi, Lysosome
Double:
Mitochondria, Chloroplast, Nucleus
Golgi Apparatus
Consists of flattened sacs called cisternae. Has a cis side which receives products and a trans side which is where vesicles are discharged
They receive proteins and modify them and packages the proteins into vesicles to be sent to the plasma membrane
Examples of Stem Cell Niches
Blood stem cell niches are located in the bone marrow
Hair follicles stem cell niche are found within the skin
Approaches used to estimate LUCA
Isometric Data
Radioactive Isotopes
Immunofluorescence
Used to find out if a protein is being produced in a cell
Fluorescent stains bind with specific antibodies
This can help identify the marked antibody and find out about its function
Evidence for LUCA in Hydrothermal Vents
Anaerobic
CO2 and Nitrogen Fixing
Hydrogen Dependent
Thermophilic
Vacuoles
Are a large sac that store food, water, and toxins and allows an uptake of water to provide turgidity of the cell
The Importance of SA:V Ratio
As the cell increases, the surface area to volume ratio decreases
Surface area controls the rate of exchanging materials and volume controls the rate of metabolism
Volume increases faster than SA, therefore making it harder to exchange waste and heat
This leads to the cell dividing