Lab 2 (microscopes) Flashcards
who invented the microscope
Anton van Leeuwenhoek invented the first microscope in 1668.
what are prokaryotes and Eukaryotes
Prokaryotes = bacteria and archaea, they are small, unicellular, with simple structure
Eukaryotes = protists, fungi, plants, animals. Can be Unicellular or multicellular, bigger, more complex.
How are Eukaryotes and Prokaryotes different
Eukaryotes can have membrane bound organelles that are specialized subunits that perform specific functions. This includes the nucleus which contains genetic material.
Prokaryotes don’t have membrane bound organelles, and instead of a nucleus have a region called the nucleoid where genetic material is located.
what is the plasma membrane
All cells have a plasma membrane composed of lipids and proteins that forms a barrier around the outside of the cell. The plasma membrane is selectively permeable and lets some substances in and some out.
what is cytoplasm and cytosol
Inside the cells is cytoplasm, a thick jelly like substance. the cytoplasm outside of organelles is called cytosol are holds enzymes, metabolites, RNA, coenzymes, inorganic ions, and the building blocks of amnio acis and nucleic acid, and suspended particles such as ribosomes.
how do plants vs prokaryotes photosynthesize
Plant cells are Eukaryotes and have organelles called Chloroplasts which do photosynthesis and contain thylakoids (flattened sacs with membranes that contain protein complexes needed for some photosynthetic reactions). The thylakoid membranes also contain Chlorophyll, a green pigment used to convert energy from the sun into chemical energy.
Prokaryotic cells might have thylakoids to do photosynthesis.
what are cell walls
A cell wall is found outside the cell membrane in plants, fungi, and most prokaryotes, which provides shape and strength to the cell.
what are vacuoles
Some animals, protists, and bacterial, and all plants and fungi have vacuoles that hold fluids, nutrients and waste. Plants have a central one that takes up 90% of the cell’s space, and helps maintain the rigid structure and store the food the cell makes.
how can cells move
Many cells have flagella or culia used for locomotion. Flagella are long, cilia are short and more numerous.
Amoebas have pseudopodia which are parts of the cytoplasmic body that protrude to help move.
what is Spirogyra
Spirogyra is a filamentous green alga that grows in freshwater. Oxygen bubbles adhere to the algae and bring it to the surface as a thick green scum.
what are the dark bands in cardiac muscle
In cardiac mucles irregularly spaced dark bands called intercalated discs run between cardiac muscle cells or myocytes. They connect adjacent myocytes together and help communicate between them.
what parts of the microscope magnify
The ocular lens is at the top of the microscope. It magnifies by a power of 10x.
The objective lens is closest to the slide and magnifies the object by another factor. Commonly 4x 10x 40x 100x etc.
The objective turret holds the objective lens to rotate it.
Total optical magnification = ocular power x objective
how do you focus a microscope
The coarse and fine focus knobs move the stage to focus the image.
Coarse = big increments Fine = small increments
how do you move the image in a microscope
the X axis stage adjust knob and Y axis stage adjust knob moves the stage in small, finely tuned increments to the right and left, or in and out.
how do you calibrate the eyepiece graticule
An Eyepiece graticule is a disc placed in the eyepiece of the microscope, it have 50 or 100 division on it with no scale. The graticule is calibrated using a stage micrometer, with an accurate micrometer (um) scale divided into 10 um increments. They are lined up and then the distance of one division of the graticule is calculate by um increment/graticule increments.
