Chapter 2 Flashcards
What is a light microscope
A light microscope uses like to achieve and magnification of up to 1500 times and the resolution of up to 0.2 micro metres which allows us to see individual cells and some organelles within them
What is a transmission electron microscope?
The transmission electron microscope uses electromagnets to focus a beam of electrons through a specimen producing an image up to 1 million times magnification and 0.0002 Micro metres which allows us to see more details of cell ultrastructure
What is a scanning electron microscope?
A scanning electron microscope is a beam of electrons that are sent across the surface of the specimen and the reflecting electrons are collected to produce a 3-D image with up to 500,000 times magnification and zero. 002 micro metres resolution
What is a laser scanning confocal microscope?
Laser scanning confocal microscope is a type of light microscopy that uses laser is to scan a specimen treated with a fluorescent die and the detector to produce a 2-D or 3-D image which is much clearer than a light microscope
How do you prepare a dry mount?
1) section a small slice of the specimen
2) put it on a slide
3) put a cover slip on it
How do you prepare a wet mount?
1) put a drop of water on the slide
2) place your specimen on the drop
3) place on the cover slip at an angle
How do you prepare smear slides?
1) put a drop of specimen on the slide
2) use the edge of another slide to smear it
3) place a cover slip on it
How to use a microscope
1) clips slide onto stage
2) select lowest power objective lens
3) focus using coarse then fine adjustment knob
4) use a higher power lens then re focus
How to use an eyepiece graticule and stage micrometer
1) line up the eyepiece graticule and stage micrometer
2) work out the size of one eyepiece graticule division
Magnification=
Magnification= image size/ object size
7 rules of scientific drawings
1) title
2) magnification
3) fill the space
4) label lines are parallel to page
5) no arrow heads
6) no shading
7) continuous lines
Definition of a eukaryotic cell
A complex cells containing a membrane-bound nucleus in which genetic information is stored
Cell wall
Made of Celulose and supports the cell
Centrioles
Hollow cylinders made up of microtubules which separate chromosomes during cell division
Plasma membrane
Made up of lipids and proteins regulate substance movements and contains receptor molecules for cell communication
Chloroplasts
Have a double membrane and internal thylakoids membranes which when stacked are called grana and contain fluid called stoma – they are the site of photosynthesis
Lysosome
A lysosome is a membrane-bound structure responsible for breaking down waste material and pathogens ingested by phagocytes
Mitochondria
The mitochondria are the sight of the final stages of respiration they have a double membrane- the inner one is folded into structures called Cristae And inside is the fluid matrix.
Ribosomes
Ribosomes are the site of protein synthesis and are made up of proteins and RNA
Golgi apparatus
Golgi apparatus is a group of membrane-bound sacs responsible for processing and packaging lipids and proteins and also for making lysosomes
Smooth endoplasmic rectilum
The smooth endoplasmic rectilum The network of membranes enclosing flattened sacs called cisternae responsible for lipids and carbohydrates synthesis and storage
Rough endoplasmic rectilum
The rough endoplasmic rectilum Is a network of membranes enclosing flattened saves called cisternae that have ribosomes attached to its surface for protein synthesis and transport
Nucleus
The nucleus contains the genetic information as DNA and controls most cells activities also contains chromatin
Nucleolus
The nucleolus is an area within the nucleus composed of RNA and proteins which are used to create ribosomes
Nuclear envelope
The nuclear envelope is a double membrane surrounding the nucleus which contains pores to control the movement of substances
Cilia
Cilia are made up of microtubules in a 9+2 formation which move substances along the cell surface
Flagella
Flagella Is also made up of microtubules in a 9+2 formation and used for cell mobility
The interrelationship between the organelles in the production and secretion of proteins
1) Proteins are synthesised at the ribosomes on the rough endoplasmic reticulum
2) They pass into the cisternae of the rough endoplasmic reticulum where they are packaged into transport vesicles
3) The vesicles are transported to the Golgi apparatus via the cytoskeleton
4) At the Golgi apparatus they are processed further
5) Finally they are packaged into secretory vesicles to be transported out/around the cell
What parts make up the cytoskeleton and what are their functions?
Microfilaments – contractile fibres formed of actin responsible for cell movement and support organelles
Microtubules – proteins Cylinders that determine the shape of a cell and act as tracks for the movement of organelles
Intermediate fibres – give mechanical strength to cells and help maintain their integrity
What are the differences between eukaryotic and prokaryotic cells
Size – prokaryotic cells are one 10th of the size of eukaryotic cells
Reproduction – prokaryotic cells reproduce through binary fission whereas eukaryotic cells reproduce through a sexual/sexual reproduction
Prokaryotic cells have fewer organelles and no membrane-bound organelles
Prokaryotic cells have circular (not linear) DNA which is free-floating in the cytoplasm And extra chromosomal DNA
Prokaryotic cells have small ribosomes
Prokaryotic cells have a cell wall made of peptidoglycan
