Unit 2 part 2 Flashcards
Cell Types
Cytology?
Branch of bio that studies all facets of the cell
Magnification?
The increase in an objects image size compared to its actual size
Resolution?
Minimal distance between two objects at which they can still be distinguished as two
Magnification + actual length formula
Magnification = Measured Length/ Actual Length
Actual Length = Measured Length/ Magnification
How do light microscopes work?
Uses light passing through living or dead spicemen to form an image
How do electron microscopes work?
Use electrons passing through spicemen to form an image
Qualities of light microscopes
- inexpensive to purchase and operate
- Simple and easy spicemen preparation
- Magnifies up to 2000x
- Spicemens may be living or dead
Qualities of electron microscopes
- Expensive to purchase and operate
- Complex and lengthy spicemen preparation
- Magnifies up to 500,000x
- Spicemen are dead, and must be fixed in a plastic material
Field of vision/ view
Total area visible when looking through a microscopes eye or ocular
How can a diameter be calculated?
Using special micrometers
Qualitative data?
- Non-numerical but descriptive data
ex. colours, presence of structure/ feature, sex, etc
Quantitative data?
Numerical values collected by a specific type of instrument
ex. mass by lab balance, length by ruler, etc
What are the two types of electron microscopes (EM)?
- Scanning electron microscope 9=(SEM)
- Transmission electron microscope (TEM)
Scanning electron microscope (SEM)
- Uses a beam of electrons to scan the surface of a spicemen
Transmission electron microscopes (TEM)
- Aims a beam of electrons through a very thin section of a spicemen that allows its inner structure to be viewed
What are the techniques employed when working with electron microscopes (EM)?
- Freeze fracture
- Cryogenic electron microscopy
Freeze fracture?
Process of preparing for observation with an EM
- Involves the rapid freezing of a biological spicemen followed by physically breaking it apart
Cryogenic electron microscopy?
Uses computer enhancement that shows 3D framework of protein involved in function of cell
- Utilizes low temps to freeze Spicemens in ice
Preparation techniques for using light microscope
- Fluorescent stains
- Immunofluorescence
Fluorescent stains
Substances/ dyes that combine with specific cellular components allowing scientist to study location, distribution, and quantity of specific biomolecules
- When fluorescence occurs assorted colours are produced
Immunofluorescence
Involves antibodies that have dyes already combined w/ them
- Allows the target, usually a protein, to be detected
- Often used to detect viral proteins that have infected cells
Condenser?
- Located between stage + light source and possesses a lens that directs light rays from light source to spicemen
3 types of light microscopes?
- Brightfield
- Darkfield
- Phase-contrast
Brightfield LM?
Most common and easy to use light microscope
- Visible light is used
- Spicemen is viewed against a light background
Darkfield LM?
Spicemen appears light against a dark background
- Special opaque lens is used in the condenser that blocks direct light from entering spicemen
Phase-Contrast
Special condenser with a circular diaphragm
- Modified objective lenses are used to reveal detailed images of spicemen w/out staining
All cells posses what common structures?
DNA
- As genetic material
Cytoplasm
- composed mainly of water
Plasma membrane
- Composed of lipids that surrounds the cytoplasm
Matrix?
- An unstructured semi-fluid region w/in a boundary
Cytosol?
- A matrix composed mainly of water and fills up the boundary of a cell
2 Types of prokaryotic cells?
Bacteria
- Member of domain eubacteria
Archae
- Member of domain archae
Pathogenic?
Disease causing
Prokaryotes are not usually pathogenic
Prokaryotic cells
Have simple cell structure w/out compartmentalization
What does a prokaryotic cell consist of?
- Ribosomes
- Plasma membrane
- Cytoplasm
- Nucleoid region
- Cell wall
- Pili
- Flagellum
Ribsomes (prokaryotes + eukaryotes)
Double layer of phospholipids that separate the interior of cell from outside environment
- Used in protein synthesis
- Controls what enters + exits cell Prokaryotes = 70s, Eukaryotes = 80s
Plasma membrane (prokaryotes)
Controls the movement of substances in and out of the cell
Cytoplasm (prokaryotes + eukaryotes)
Cite of chemical reactions w/in the cell (metabolism)
Nucleiod region (prokaryotes)
irregularly shaped region that contains DNA
- Usually in the form of circular double strand
Cell wall (prokaryote)
Provides structural support and prevents cells from bursting
- Made of peptidoglycan
Pili (prokaryotes)
For adhesion and to transfer genetic material between bacteria (sexual reproduction)
- Bacillus bacteria = pili
- Staphylococcus = no pili
Binary Fission
A process that divides prokaryotic cells
- Dna is copied = 2 daughter chromosomes
- Daughter chromos to different regions on plasma membrane
- Cell then divides into 2 genetically identical daughter cells
Eukaryotic cells
Have chromosomes located in nucleus and a variety of of membrane bound organelles
- Animals, plants, and fungi = eukaryotic
What does a eukaryotic cell consist of?
- Plasma membrane
- Cytoplasm
- Ribosomes
- Nucleus
- Chromosomes
- Mitochondria
- Vacuoles
- Lysosomes
- Rough + Smooth ER
- Golgi apparatus
- Cytoskeleton
Nucleus (eukaryotes)
Has chromosomes associated w/ histones protein in nucleus
- Has double membrane w/ pores that allow mRNA to enter cytoplasm
Chromosomes (eukaryotes + prokaryote)
Composed of DNA wrapped around histone protein
- Dna is genetic material for growth and development of cell
Prokaryote = 1, loop of DNA
Eukaryote = Many, linear
Mitochondria (eukaryote)
Aerobic respiration producing ATP
- Has inner folded membranes known as cristae
Vacuoles (eukaryote)
Plants = large for storing nutrients
Animals = small and involved in removal of waste
Lysosomes (eukaryotes)
Specialized enzymes containing enzymes involved in digestion of large molecules
- Not usually found in plants
Rough endoplasmic reticulum (eukaryote)
Membrane structure that’s the site for protein synthesis and is involved w/transporting proteins to golgi apparatus
- ribosomes attached
Smooth endoplasmic reticulum (eukaryote)
Involved in lipid synthesis and detoxification
- Doesn’t have ribosomes attached
Golgi apparatus ( eukaryote)
Modifies and packages proteins to be exported from the cell
Cytoskeleton (eukaryotic + prokaryotic)
Composed of protein microtubules, involved in maintaining cell shape, moving organelles, and nuclear division (mitosis and meiosis)
What are the functions of life all cells must carry out, multicellular or unicellular?
- Metabolism
- Growth
- Reproduction
- Response to stimuli
- homeostasis
- Nutrition
- Excretion
- Movement
Homeostasis
Maintenance of internal conditions w/in a narrow range
Response to stimuli
Ability of organisms to respond to internal or external stimuli
Cell wall (eukaryote)
Animal = yes
Pldant = cellulose
Fungi = chitin
vaculosed (eukaryote comparison)
Fungi = small or large depending on species
Plant = Large central vacuole involved in storing nutrients + waste and helps maintain turgor pressure
Centrosome (eukaryotes)
Animal = yes + involved in mitosis
Fungi = no
Plant = no
Plastids (eukaryotes)
Only in plants cells
Chloroplast (eukaryotes)
Carries out photosynthesis
- Only found in plants and algae
Eukaryotic cells that don’t have a nucleus
- Skeletal muscle cells
- Red blood cells
- Phloem sieve tube elements
Endoplasmic theory
Suggests that a large cell engulfed a small aerobic prokaryotic cell
- Evidence suggests all eukaryotes evolved from a common unicellular ancestor that had a nucleus and reproduced sexually
Host cell?
Provides protection received ATP energy from aerobic cell
Evidence for endosymbiotic theory
Chloroplast + mitochondria are a similar size to modern prokaryotes and share many characteristics which support the theory (70s ribosomes, binary fission)
Ocular micrometer
AKA graticle located in eyepiece and is engraved w/ equal units
Peptidedoglycan
Carbohydrate protein complex
Capsule
Layer of a type of polysacharide outside of cell wall
Nucleosome
Combination of DNA and histone
Basal bodies
Structure relates to centrogones of eukaryotic cells and are located at base of cilia and Flagellum
