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Microscopy and the Cell
What are the differences between magnification and resolution? Magnification is the ratio of
an image to the actual size. Resolution is the clarity of the image.
Light microscopes are used with living cells.
True/False
What parameter in the use of light microscopes can be improved by staining? Contrast
Light microscopes have limited power as they can’t resolve detail smaller than 0.2 micrometers.
To see at this level, a different type of microscope is used. What is this microscope called?
Electron microscope
Electron microscopes are used to observe viruses and organelles. True/False
What is the difference between transmission and scanning electron microscopes?
Transmission are used for studying the internal components, while scanning are used for
studying the surface.
Describe cell fractionation.
Cells are homogenized in a blender to break them apart. Then the components are spun at
high speeds in order to separate them out. This enables researchers to observe individual
organelles.
Describe the differences between viruses, prokaryotic cells, and eukaryotic cells (reproduction,
DNA, organelles, size, etc.). You may draw a table like the one from class.
Viruses aren’t considered to be living, they are extremely tiny (about 100 times smaller
than bacteria), and they consist of a protein coat surrounding nucleic acid.
Prokaryotes are unicellular, reproduce asexually, have cell walls of peptidoglycan, much
smaller than eukaryotes, lack organelles, and have a nucleiod region of circular DNA.
Eukaryotes are uni and multicellular, reproduce asexually/sexually, linear DNA in the
nucleus, organelles, larger than prokaryotes, oxygen metabolism.
Does a whale have larger cells than a hummingbird? No
Cytoplasm is the region between the nucleus and the plasma membrane.
Why is the surface area to volume ratio important for cells? The more surface area, the more
materials can be taken in per unit volume.
Describe the function of the plasma membrane. It is used for cell adhesion and as a selective
barrier for allowing the passage of materials to and from the cell.
The nucleus is the most noticeable organelle in eukaryotic cells. This organelle is double
membraned and contains pores. It contains most of the genes for the cell.
Chromosomes are organized units of RNA. True/False
Name the components of chromatin. Proteins and DNA
What is the function of the nucleolus? Ribosome construction
The region that houses DNA in prokaryotic cells is called the
nucleoid
region.
What component of cells carries out protein synthesis? Ribosomes
Organelles
allow eukaryotic cells to carry out many functions simultaneously.
Rough endoplasmic reticulum is important for the synthesis of oils, phospholipids, and steroids.
True/False
What is the purpose of the Golgi apparatus?
Modifies proteins and phospholipids, synthesis of polysaccharides, and ships products out
in vesicles
In animal cells,
of cell suicide.
lysosomes
are used as a means to recycle organelles along with the process
Amoebas engulf their food through a process known as phagocytosis. True/False
What process occurs when a lysosome fuses with a double membrane enclosed around cellular
organic material to recycle that material?
Autophagy
Name and describe the three types of vacuoles.
Food- encloses food engulfed through phagocytosis
Contractile- pump excess water out of the cell to maintain ion concentrations
Central- in plants, stores organic compounds, holds inorganic ions, disposal site for
chemical biproducts, and other functions
Compare and contrast the mitochondria and chloroplasts.
Mitochondria are the site of cellular respiration, while the chloroplast is for photosynthesis.
Both have circular DNA, divide through binary fission, closely related to bacteria.
Cytosol gives cells support and helps them maintain their shape. True/False
Name the two structures for motility in cells. Flagella and cilia
Animal cells lack a cell wall, but instead they have the
extracellular matrix
. This
consists of many glycoproteins, the most common of which is collagen . Fibronectin is one
glycoprotein that connects it to the integrins or cell surface receptor proteins located within
the plasma membrane.
What connects the plants cells through the cell walls to form a single organism? plasmodesmata
Describe the difference between gram positive and gram negative bacteria.
Positive- cells with a thick layer or exposed peptidoglycan
Negative- thin layer of protected peptidoglycan