biology part 1 Flashcards
microscopes- prokaryotes
what is the formula for microscopy
measured size/ actual size
m= i/a
what is the function of the course focus
An unclear focus
what is the function of the fine focus
a clear view
what is the function of the objective lens
brings the cell to focus
what is the function of the stage
Supports the specimen
what is the function of the light source
A source of light that helps sees the specimen clearer
what are the disadvantages of using a light microscope
the wavelength of the light limits the microscope from seeing inside of the specimen.
what is the formula for total magnification
magnification of the eyepiece lens X magnification of the objective lens.
what magnification does the eyepiece usually have
x10
what is the greatest magnification of the objective lens
x100
what is the greatest total magnification
x1000
How do you set up a specimen
- the specimen must be thin so that a light/ electron beam can pass through.
- a coverslip is needed to protect the specimen and lens from touching.
- Stains can help distinguish different features of the specimen.
what are the disadvantages of using an electron microscope
it can only examine dead specimens,
what are the advantages of using an electron microscope
it has a shorter wavelength allowing us to see more details in the specimen
what is the formula for actual size
Measured size/ magnification
what structures can a light microscope see
DNA
Plasma membrane
ribosomes
cytoplasm
what structures can an electron microscope see
Plasma membrane Rough ER Smooth ER Mitrochondia Cytoplasm ribosomes golgi apparatus lysomome centrioles nucleus vesicle nucleolus
what is the function of the Plasma membrane
- protects the cell from its surroundings
- regulates the movement of substances in and out of the cell.
what is the function of the Rough ER
- series of single, flattened sacs
- surrounded by ribosomes on the surface.
- proteins made here
what are prokaryotes
bacteria, they are made of single cells with no membrane-bound organelles
what is the function of the smooth ER
- A series of single, sacs made of membrane.
- lipids are made here.
what is the function of the mitochondrion
- surrounded by a double membrane.
- inner membrane folded into finger-like projections called cristae.
- central area contains a jelly called the matrix.
- contains ribosomes and DNA
- site of respiration
what is the function of the cytoplasm
- Fluid that fills a cell
- dissolves molecules in a solution (enzymes, sugars, amino acids and fatty acids)
- site of metabolic processes
what is the function of the ribosome
-site of protein synthesis
what is the function of the Golgi apparatus
- series of single, curved sacs enclosed in a membrane.
- vesicles cluster around the Golgi.
- modifies proteins and packages them in vesicles for transportation.
what is the function of the lysosome
- enclosed by a single membrane
- contains digestive enzymes
- destroys old organelles and pathogens
what is the function of the centrioles
- two hollow cylinders
- arranged at right- angles to eachother
- makes the spindle in cell division
what is the function of the nucleus
- surrounded by a double membrane
- holes in the nuclear membrane
what is the function of the vesicle
- small, membrane-bound sac
- transports and stores substances in the cell.
what is the function of the nucleolus
- region of dense DNA and protein.
- makes ribosomes.
what is the bacteria cells structure
- plasmids
- capsule
- ribosomes
- nucleoid
- cell wall
what is the function of the what is the function of the plasmids
- double-stranded DNA in a circular structure
- contains additional genes that aid the survival of the bacteria, e.g.antibiotic resistance/ toxin-producing genes
what is the function of the capsule
- polysaccharidde layer outside the cell wall.
- protects cells from drying out, or being engulfed by white blood cells.
- helps cells to stick to surfaces
what is the function of the cell wall
- provides support and protection
- made of long-chained molecules made up of a sugar and amino acids called peptidoglycan
what is the function of the nucleoid
- region where single circular, length of DNA is folded.
- DNA carries information
what is a gram-negative bacteria
they dont retain the gram stain when washed with acetone and absolute alcohol because the cell wall has an outer layer.
what is a gram-positive bacteria
they retain the gram stain because the thick peptidoglycan wall absorbs the sain and they dont have an outer layer of cell wall
why are gram-negative bateria more resistant than gram-postive bacteria
gram-negative bacteria are more resistant to antibiotics than gram-positive because gram negatives have an outer membrane on its cell wall which protects them from bacteria
how do you get from 1000 micrometres ( μm) to 1 millimetre (mm)
1000μm = 1mm
how do you get from 1000 nanometers (nm) to 1 micrometre( μm)
1000nm= 1 μm
How do you get from 1000000 nanometers (nm) to 1 millimetre ( mm)
1000000nm = 1mm
how do you go from nm to μm to mm to cm to m
divide by 1000 unless your converting cm to m which is when you divide by 10
How do you go from m to cm to mm to μm to nm
times by 1000 unless your converting m to cm which is when you times by 10
what is the structure of chloroplast
- has a double membrane that is filled with a liquid called stoma.
- contains stacks of thylakoid membranes called grana.
- thylakoid membranes are the site for photosynthesis.
what is the structure of the vacuole
-a membrane called tonoplast which is filled with cell sap.
what is the structure of the Golgi complex
-has smooth membranes forming the cell
what is the structure of lysosomes
-contains hydrolytic enzymes to digest materials in the cells
what is the function of tonoplast membrane
controls movement of molecules into and out of the vacuole
what is the function of the amyloplasts
stores starch
what is the function of the middle lamella
sticks cells together
what is the function of the plasmodesmata and pits
allows communication between one cell and another
what are the parts of the plant cell
- chloroplast
- vacuole
- tonoplast membrane
- cell wall
- amyloplasts
- middle lamella
- plasmodesmata and pits
what are the parts of the animal cell
- plasma membrane
- rough ER
- smooth ER
- mitochondrion
- ribosomes
- golgi apparatus
- lysosomes
- centrioles
- nucleus
- vesicle
- nucleolus
- cytoplasm
