Prokaryotes and Eukaryotes Flashcards
What is an Organism?
Organisms are made of CELLS of which are the smallest fundamental units of life
What are the two types of organisms?
1) Unicellular
2) Multicellular
What is a Unicellular Organism?
All bacteria, fungi, yeasts, algae
What is a Multicellular Organism?
1) Parasites (not protozoa)
2) Pluricellular fungi such as moulds, algae
3) Plants (Onion Cells)
4) Animals (Epithelial Cells)
What determines a cells specific specialisation?
The shape and size of the cell
What are red blood cells?
A blood cell made in the bone marrow and found in the blood
What do red blood cells contain? And their function?
Contain a protein called Haemoglobin, which carries oxygen from the lungs to all parts of the body. Does not contain a nucleus
What shape is the red blood cell?
Biconcave shape, small and flexible
What is the function of a nerve cell/ neuron?
To transmit electrical impulses to other nerve cells, muscles or gland cells in response to environment stimuli
What is the shape of a nerve cell/ neuron?
Thin and long; branched at their ends; different sub cellular parts; release if neurotransmitter signals
What is a light/optical microscope used for?
To observe living cells in a tissue and some internal structures.
What does magnification mean in terms of a microscope?
The ratio of an objects image to its real size. Objective X ocular lens. The limit is around X1000
What does resolution mean in terms of a microscope?
It is the ability to distinguish between two very closely positioned objects. The limit is about 0.2um
What is a Fluorescence microscope used for? and how does it work?
To visualise and monitor the localisation of labelled molecules within a cell or tissue.
Works through excitation of fluorophores which detects fluorescence signals
Diagram of Fluorescence Microscope
Diagram of Light/Optic microscope
What are the two main types of electron microscopes?
Transmission EM (TEM)
Scanning EM (SEM)
What is a Transmission EM (TEM) microscope?
It is an electron microscope which is used to study organelles
What is a Scanning EM (SEM) microscope?
It is an electron microscope which is used in order to study the cell surface
What is an electron microscope used for?
Technique for obtaining high resolution images, using a beam of electrons (very short wavelengths) as the source of illuminating radiation
Provides a detailed structure of cells, organelles and macromolecule complexes
Living cells can not be observed
Can living cells be observed through an electron microscope?
No
Can you see living cells through a microscope?
They must be stained to be visible in a traditional light microscope- which can kill them
What parts of a cell do all cell types have?
- Plasma membrane
-Cytosol
-Ribosomes
-DNA molecules
What is a plasma membrane?
What is the cytosol?
A concentrated aqueous solution of chemicals
What are ribosomes?
perform biological protein synthesis
What are DNA molecules?
They are molecules which carry hereditary information, defining each species
All genetic information of a cell is defined as what?
A Genome
What are Macromolecules in cells?
They are polymers made by specific repeating molecular units, monomers
What macromolecules are found in cells of all organisms?
-Carbohydrates/Polysaccharides
-Proteins
-Lipids
-Nucleic acids
What is a monomer?
What is a polymer?
What is a polymerisation or condensation reaction?
What is anabolism?
What is hydrolysis/catabolism?
The process of which POLYMERS can be broken down into SMALLER molecules again. The process is called CATABOLISM
What is Catabolism?
the breakdown of complex molecules in living organisms to form simpler ones
What is the equation for Metabolism?
Catabolism + Anabolism = Metabolism
Monomer and Polymer diagram
What is a Prokaryotic Cell?
-Without a nucleus
-Only one compartment surrounded by a plasma membrane
-Has NO organelles
-Simple internal organisation
What is a Eukaryotic cell?
-With nucleus
-Internal membranes that enclose the organelles
-Complex organisation
What cell is smaller Prokaryotic or Eukaryotic?
Prokaryotic cell is smaller (0.1-5um)
Prokaryotic cells are divided into two domains. What are they?
Bacteria and Archaea
What is the difference between Bacteria and Archaea?
They are structurally similar but have different biochemical abilities.
Archaea live in normal habitats, most grow in extreme environmental conditions
Bacteria
Prokaryotic cell structure diagram
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What are the surface layers of a prokaryotic cell?
-Plasma membrane
-Cell wall
-Glycocalyx
What is a plasma membrane?
Flexible lipid bilayer membrane made up of phospholipids and proteins.
DO NOT contain sterols
It controls the movement of molecules across the cell and protects the internal composition
What is the cell wall?
A rigid structure composed of peptidoglycan
Maintenance of cell shape and structural integrity
What is Glycocalyx?
A capsule or slime layer composed of polysaccharides or polypeptides
It protects the cell against dehydration, immune system (phagocytosis) and antibiotics. It is also an adherence factor
What is the intracellular composition of a Prokaryotic Cell?
-Cytoplasm
-Ribosomes
-Single circular genomic DNA in nucleoid. NO NUCLEUS
-Inclusion bodies
-Plasmids
What is the Cytoplasm?
What are ribosomes?
What are plasmids?
What are Appendages?
What are the Appendages in Prokaryotic cells?
-Flagellum
-Fimbriae/ filli
-Sex pilus/ pilli
What is Flagellum?
Whip-like structure, locomotion movement and acts as a sensory structure
What is Fimbriae/Filli
organelles expressed on the surface of bacteria
What is sex plus/ pilli ?
Appendage which it attaches to a female bacterium, preparatory to the transfer of DNA from male to female.
Where are Eukaryotic cells found?
Found in Unicellular Organisms (Protozoa and yeasts)
Found in Multicellular organisms (animals)
Is the cell wall present in animal and human cells?
No, a cell wall is only found in plant cells
Do eukaryotic cells or prokaryotic cells have a nucleus ?
Eukaryotic cells
Diagram of Eukaryotic cell
What organelles are only present in Eukaryotic cells?
-Nucleus
-Mitochondria
-Endoplasmic Reticulum
-Golgi apparatus
-Peroxisomes
The organelles in Eukaryotic cells are…
Membrane-bound structures allowing compartmentalisation so that other kinds of biochemical reactions can take place in specific sites.
Every organelle has one or more internal compartments
What are Lysosomes?
Digestive enzymes
Where are Lysosomes found?
Organelles only found in animal cells
What are Chloroplasts?
Where are Chloroplasts found?
Organelles only found in plants
What are the Eukaryotic cell components?
-Cytoplasm
-Cytosol
-Ribosomes
-Cytoskeleton
What is a Microfilament ? and where is it found?
What is an intermediate filament? and where is it found?
What are microtubules? and where are they found?
There are major components of the cytoskeleton. They are found in all eukaryotic cells, and they are involved in mitosis,
Multicellular organisms depend on what?
-interaction of specialised cells
List 3 cytoskeleton filaments from the thickest to the thinnest?
-microtubules
-Intermediate filaments
-Microfilaments
Monomers join together via what?
-condensation (or polymerisation) reactions
