Cell Structure and Varieties Flashcards
Define a cell
An aqueous mixture of chemicals bound by a small membrane with reproductive capacity
What is the cell diameter range?
1-100um
What are the size differences between prokaryotic cells and eukaryotic ones?
Pro = 0.2-2.0um
Eu = 10-100um
When it comes to carbon source, where does organism labelling differ?
Hetero means living carbon source, autotroph means inorganic compound
What is a lithotroph and organotroph?
Lithotroph is a chemoautotroph and organotroph is a chemoheterotroph
Who built the first microscope?
hooke
Who are the two investigators that led up to cell theory?
Schwann - Animals are made of cells
Schleiden - Plants are made of cells
What is cell theory (1838) and what is the addition?
Cells are the fundamental units for life
All living organisms are composed of cells
All cells come from preexisting cells
Addition:
Modern cells evolved from a common ancestor
What kind of microscope is used to visualize living cells? What is its mag?
A light microscope has a resolution of about 200nm., or 1000x human
What are the 6 types of light microscopy?
- Bright field microscopy
- Phase contrast microscopy
- Differential inference contrast microscopy
- stained bright field microscopy
- fluorescence microscopy
- confocal microscopy
Describe Bright field microscopy
Light directly through the cells, low contrast, low details
Describe Phase contrast microscopy
Contrast is increased through refraction
Describe Differential inference contrast microscopy
Two beams of light to make a shadow
describe stained bright field microscopy
bright field but stained
describe fluorescence microscopy
microscopy with light stimulating a fluorescent material/dye
describe confocal microscopy
fluorescence microscopy except with a manipulation of light that gives a sharper 2D image
What is a electron microscope?
It directs electrons through a vacuum at a screen to create an image
What is the resolution of an electron microscope?
2nm, 100,000x human
What are the two types of electron microscopes?
TEM(transmission) and SEM(scanning)
What is the drawback of electron microscopy?
Only deals with dead cells
What is TEM?
Magnets shooting electrons at an object that absorbs them or not
What is SEM?
Electrons being shot at samples that release more electrons that are measured
What is cytosol?
The fluid inside the cytoplasm (everything but the nucleus) that is not contained.
What is the structural difference between prokaryotes and eukaryotes?
Prokaryotes have no organelles
What 4 things do all prokaryotic cells have?
- Cell membrane
- Nucleoid
- Cytoplasm
- Ribosomes
What would a prokaryotic cell wall and capsule be made of?
Cell wall - peptidoglycan
Capsule - Polysaccharides
What are the three functions of prokaryotic cell capsules?
- Protect from attack
- Keep from drying out
- Help bacteria attach to other cells
What is the structural difference between a gram positive or gram negative bacteria?
Gram positive bacteria have thick peptidoglycan layers but no lipid layer, and gram negative have thin peptidoglycan layers and a lipid membrane
What are the two bacterial cytoskeleton proteins?
MreB, FtsZ at site of division
What is the difference between fimbriae and pili?
Pili are bigger and used for genetic exchange
What is the flagellum responsible and what is it composed of?
It is responsible for the motility of the bacteria and is composed of Flagellin protein
What are the three parts of a flagellum?
The basal body, hook, and filament
What happens in the endoplasmic reticulum?
Protein/lipid synthesis
What is the purpose of the Golgi apparatus?
It packages and distributes proteins
What is the purpose of the lysosome vs endosomes?
lysosomes deal with intracellular degradation, and endosomes sort exocytosed matter
What process creates ATP in the mitochondria?
oxidative phosphorylation
What do peroxisomes do?
They oxidize toxic molecules
Describe the structure of a nucleus
The nucleolus is surrounded by the nucleoplasm, which is under the nuclear lamina contained by the nuclear envelope, with holes called nuclear pore. Chromosomes and chromatin are found in the nucleoplasm.
What happens in the nucleolus?
Ribosomal RNA synthesis and ribogenesis (ribosome assembly)
What is nuclear lamina involved in?
DNA replication, RNA transcription, organization, cell development, assembly, reproduction
What is progeria?
It is a genetic condition of rapid ageing in children
What are chromosomes made of?
Chromatin
