The Cell Part 1 Flashcards
Cell
the smallest living unit of all living things
Microscope
an instrument used to observe small objects such as cells by making enlarged images of them
What is the modern cell theory?
It is a compilation of discoveries that is now considered a fundamental concept of biology.
How many parts does the modern cell theory consist of?
3 statements
What are the statements that make up the Modern Cell Theory?
1) The cell is the fundamental structure and function in living things.
2) All living things are composed of cells
3) Cells come from pre existing cells.
When were the first magnifying objects made?
1550s
What were the first magnifying objects? and who made them?
Eyeglasses combined to make magnifying objects made by Eyeglass makers in Europe
Why is Robert Hooke important?
Robert Hooke was the first person RECOGNIZED to have looked through a compound microscope and discovered cells.
He thought they looked like the cork cells and thought they looked like the dorms in monasteries and therefore named them “cells.”
When did Robert Hooke discover cells?
1665
Who was Matthias Schleiden?
Matthias Schleiden was a botanist that stated that all plants are made of cells.
Who was Theodor Schwann?
Theodor Schwann was a zoologist who stated that all animals are made of cells.
Who was Anton Van Leeuwenhoek?
Businessman/ Scientists who used a single-lensed microscope to examine pond water, saliva in the mouth, etc. He discovered bacteria.
What did Van Leeuwenhoek call bacteria?
Animacules
What is Van Leeuwenhoek’s nickname?
Father of microscopy
When did Van Leeuwenhoek make his discovery?
1674
When did Schwann and Schleiden make their statements about animals and plants?
1830
What statement did Schwann and Schleiden come up with by working together?
All living things are made of cells.
Who was Rudolf Virchow?
A physician that stated that new cells can only be made by division of existing ones.
Was Virchow’s idea original?
No he proved Lorenz Oken’s theory.
When did Rudolf Virchow make his discovery?
1855
Most microscopes use ____ or _____ to create images
light; electrons
How many categories of types of microscopes are there? and what are they?
2; Compound light microscopes and Electron Microscopes
What are Compound Light Microscopes?
microscopes that use light, which allow light to pass through the specimen that it is viewing.
Compound Light Microscopes make micrographs in the gray scale. (True or False)
False; colored
How many lenses does a compound light microscope have? and what are they?
2; Objective Lens and Ocular Lens
Objective Lens
Lens that is located directly above the specimen -> enlarges it
(This lens can have different powers of magnification in different microscopes)
Ocular Lens
Lens that magnifies that specimen further
How close can a compound light microscope look at a specimen?
up to 1 millionth of a meter
What are the problems of using a compound light microscope?
1) Can only produce clear images of objects up to 1000x magnification bc radiation (light) scatter as it moves through matter
2) Most cells are transparent
How is transparency of cells fixed?
Use chemical stains/dyes on cells
Fluorescence Microscopy
When fluorescent dyes are used to give off a certain color, advanced techniques can attach fluorescent labels of different colors to different molecules so that scientists can see colored organisms moving (some of these methods need special microscopes)
Micrograph
photo of object seen through microscope
Specimen looked at through compound light microscopes need to be ___ and ____ to let ____ through it
thin, translucent, light
How do electron microscopes work?
1) Coat specimen in metal
2) Put specimen in vacuum so that electrons only interact with air and nothing else
3) Use beam of electrons to make micrograph
What are the beams of electrons focused by?
Magnetic Fields
Electron Microscopes make images in gray scale.
(True or False)
True
Electron Microscopes can magnify up to _______
1 billionth of a meter
Electron microscopes commonly look at….
DNA or viruses
How many types of electron microscopes are there? and what are they?
2; Transmission Microscopes (TE) and Scanning Microscopes (SE)
All specimen observed with electron microscopes must be ____
dead
What is the main purpose of transmission microscopes?
to explore cell structures and large proteins
Transmission Microscopes have _____ magnification of scanning microscopes
half
How do transmission microscopes make micrographs?
Sending electrons THROUGH the specimen
All specimen observed with transmission microscopes must be ____ because ____
ultra thin so that the electrons can pass through
Transmission Electron Microscopes make _____ micrographs (not color or grayscale)
flat and 2-D shaped because the sample has to be ultra thin
Specimen studied under Scanning Microscopes can be cut ______
Into opaque 3-dimensional objects
How do scanning microscopes make micrographs?
Shooting a lower voltage beam (skiny, pencil like) of electrons at the specimen
Scanning Microscopes have _____ magnification of transmission microscopes
double
Eu means
true
karyote means
nucelus
Contrast
the difference in brightness bewteen the light and the dark parts of an image
Disadvantage of electron microscopes
the organism has to be dead
Cyto
cell
Cytology
study of cell strcture
Cell fractionation done with what
centrifuge
Cell fractionation
the separating of cell parts
in Cell fractionation the ornganelles are taken out based on what
their size/density
the lower speeds of cell fractionation take out what
the bigger organelles
the faster speeds of cell fractionation take out what
the smaller organelles
What is the purpose of cell fractionation
to study the individual organelles’funtion structure and enzymes
As time goes on the person will spin the centrifuge faster or slower
faster
basic order of cell fractionation happening
slow speed and short amt of time and big fat come out, scoop out, put rest, faster speed, faster time, scoop out MEDIUM, put rest, repeat
Homoegenate
blended up soup that is made up of two things
Supernatant
cell soup (the liquid left over after the scoop)
Centrifuge spins at an angle
True or False
True –> to helpthe cell to separate
Pellet
the organelle that is to be scooped out
Cell
the basis structural and functional units of organisms
____ increases while ___ stays the same (fill out with volume and surface area +the reason
surface area; volume; so theres ore room for reactions and organellles while still remaiming small bc organisms can only fit certain amt of cells
miscroscopes
helps to see things that you cant see with the naked eye
resolving power
resolutionon a microscope: the minimum distance that 2 points can be separated and still seen as 2 distinct points (clarity)
magnification
ratio of size on an image to the size of the object (amount of times its increased its size)
Light microscope
uses visible light to illuminate an object (can have light bulb or mirror) and the thing you put under it is a living organissm than is thin and NOT opaque
Electron microscope
powerful in resolution and magnification, shot a tiny ray of electrons at substance
how do scanning microscopes work
scan ray of electrons (super concentrated but skinny like stick) at the substance and then the electrosbounce off
what type of microscope gets 3D images
scanning
