Cells Flashcards
(43 cards)
Microscope
An instrument that enables the human eye to observe enlarged images of tiny objects
Who was the father of microscopy?
Anton van Leewenhoek
The Cell Theory
- All organisms are made up of one or more than one cell
- A cell is the basic structural unit of all life forms on this planet
- All cells come from pre-existing cells
Metabolism
All chemical reactions within the body
Cytology
The study of cells
What is a Synchrotron?
It is a source of highly intense light ranging from infrared to hard x-rays used for a wide variety of research purposes.
How are cells classified?
By:
- Structure
- How they obtain energy
What are the two types of cells?
- Eukaryotes
- Prokaryotes
What are Eukaryotes?
All cells that have a membrane around the nucleus and they have membrane bound organelles.
What are Prokaryotes?
Organisms that consist of cells without a membrane around the nucleus, e.g. bacteria
What are the types of microscopes?
- Light microscope
- Scanning Electron Microscope (SEM)
- Transmission Electron Microscope (TEM)
What is a light microscope?
- It is the simplest form of microscope.
- The specimens are illuminated with light
- All light microscopes use several lenses to obtain high magnification.
- It can be magnified up to 400 times.
How do you work out the magnification?
Eyepiece number X objective lens number = Magnification
E.g. 4x scanning objective X 10x eyepiece = 40x
What is a Scanning Electron Microscope (SEM)?
- SEM use electron illumination
- The image is seen in 3D
- The pictures are in black and white
- The cells are dead
What is a Transmission Electron Microscope (TEM)?
- TEM is electron illuminated
- It gives a 2D view
- Thin slices of specimen are obtained
- It has high magnification and high resolution
- The cells are dead
How are Prokaryotes clssified?
- Eubacteria
- Archaea
What is Eubacteria?
- It is generally talking about bacteria
- They are complex structures that are found under neutral conditions
- You can find Eubacteria in the human body, in some foods and practically everywhere around us
What are Archaeans?
- They are single-celled prokaryotes
- They can exist under some of the most extreme conditions, such as extremely hot, acidic or alkaline environments
- They are also known as Extremophiles
What is the structure of a Prokaryote cell?
- Plasma membrane
- Cytoplasm
- Ribosomes
- DNA
- Plasmid
- Cell wall
- Flagellum
- No membrane bound organelles
- Capsule inside the cell wall
What are photosynthetic prokaryotes?
-They do not contain chloroplasts but they possess membranous vesicles called thylakoids, where pigments (chlorophyll molecules) enable radiant energy of sunlight.
What are chemosynthetic prokaryotes?
-They obtain energy to make their organic food by oxidizing high-energy inorganic compounds instead of consuming organic nutrients or using sunlight.
What is the structure of a Eukaryote cell?
- Plasma membrane
- Cytoplasm
- Membrane bound nucleus and organelles
What kingdoms are eukaryote cells divided into?
- Plants
- Animals
- Protists
- Fungi
What is a plasma membrane?
- A thin membrane surrounding the cell
- Keeps the cells shape
- Separates the changing surrounding environments and allows certain liquids and gases to pass through it