Lesson 3: Cell Structure Flashcards
What is magnification?
ratio of image size to object size
What is resolution?
the ability to distinguish between objects that are close together.
What are some features of the optical microscope?
lower magnification (x2000) and resolution.
Less expensive
preparation of specimen is simple
specimen can be dead or alive.
What are some features of electron microscopes?
higher magnification (x500,000) and resolution.
more expensive
preparation of specimen is complex.
specimen must be dead.
Magnification equation
Magnification = image size / actual size
Structures common to all cells
Genetic material
Cytoplasm
Cell membrane
Ribosomes
What are some features of prokaryotes?
Simpler and smaller
no membrane-bound organelles
Nucleoid Region
70s ribosomes
Cell wall made of peptidoglycan (murein).
Flagella does not have a 9+2 arrangement.
Capsule
Nucleoid region
Consists of a singular supercoiled chromosome and small loops of DNA called plasmids.
plasmids contain genes that can be passed between prokaryotes.
Why is compartmentalization important in eukaryotic cells?
- damaging substances kept separate
- optimal conditions for certain processes
- # + location of organelles can be altered
Plant cells vs. Animal cells
Plant cells have a large and permanent vacuole, cell wall and chloroplast.
Animal cells have lysosomes and centrosomes.
Function of Nucleolus
creates ribosomes to go and latch onto the rough ER.
Function of nuclear envelope
has nuclear pores to let relatively large molecules to pass through.
Function of mitochondria
site of aerobic respiration
Function of ribosomes
site of protein synthesis.
Function of free ribosomes
makes proteins for the cell.
Function of bounded ribosomes
makes proteins that will be secreted (released) from the cell.
Function of golgi apparatus
Modifies and packages proteins from the rough ER into secretory vesicles to be secreted out of the cell.
Function of lysosomes
contains powerful hydrolytic digestive enzymes used to break down material.
Function of rough endoplasmic reticulum
proteins produced by the bound ribosomes move into the lumen (space) to be packaged into vesicles that go to the golgi apparatus.
Function of smooth endoplasmic reticulum
lipid synthesis, detoxification and storage of calcium ions in cell.
Function of cytoskeleton (centrioles)
provide mechanical strength to cells and enables cell movement.
Function of vacuole
uptake of water for rigidity of plant cell and stores nutrition.
Function of chloroplast
site of photosynthesis.
Explain the process of endosymbiosis
Large prokaryotic cells engulfed smaller ones.
Some engulfed cells could use oxygen to make energy (became mitochondria).
Others could use sunlight to make energy (became chloroplasts).
What are some evidence for endosymbiosis?
Mitochondria and chloroplasts have their own DNA, separate from the nucleus.
Their sizes are similar to bacteria.
Binary fission is similar to bacteria.
Contain 70s ribosomes which are only present in bacteria cells.
What are the walls of plant cells made of?
cellulose
What do plant cells store carbs as?
starch
what is the shape of plant cells?
Rigid and fixed in shape
what are fungi cell walls made of?
chitin
what do fungal cells store carbs as?
glycogen
Which ones do fungal cells have (flagella, cilia, basal bodies)?
has cilia, flagella but no basal bodies
Which ones do animal cells have (flagella, cilia, basal bodies)?
all
Which ones do plant cells have (flagella, cilia, basal bodies)?
none
What are some evidences for LUCA in general?
All cells share the same genetic code.
All cells use DNA and RNA as their genetic information.
All living organisms have similar transport mechanisms in and out of the cell.
Why is a large SA:V ratio important?
increased rate of exchange (waste + opposite of waste)in cells
