Chapter 4 Flashcards
Cytology is the
study of cells
The different types of microscopes are _(2)
1) Light microscope (what we use in class)
2) Electron microscope
a) Transmission electron miscroscope (TEM) (directs electrons through thin-cut sections)
b) Scanning electron microscope (SEM) (electons through surface of specimen…this is more powerful than TEM)
Cells vary greatly in ___ and _
Size (7-120 picometer?)
Shape (spherical, tubelike, column like, cylindrical, etc.)
The plasma membrane
1)forms outer limiting barrier (separates internal contents from external environment)
What are some modified extensions of the plasma membrane _(3)
Cilia
flagellum
microvilli
The nucleus is/has _(3)
1)largest strucure in the cell (enclosed by a nuclear envelope)
2)contains genetic material (DNA); also contains a nucleolus
3)nucleoplasm(inner fluid)
The cytoplasm is/has
1)the cellular contents between the plasma membrane and the nucleus
2)includes: cytosol, organelles, and inclusions
What is cytosol _(2)
1) The intracellular fluid that is viscous and has a high water content
2) It contains dissolved macromolecules and ions
Organelles are _
1)little complex organs within cells
2)Unique shapes and functions
The two types of organelles are _
1)membrane-bound organelles
2)non-membrane-bound organelles
Membrane-bound organelles are _(3)
1) enclosed by a membrane
2) Separates contents from cytosol
3) Includes endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria
Non-membrane-bound organelles are _
1)not enclosed within a membrane
2)composed of protein
3) includes ribosomes, cytoskeleton, centrosome, proteasomes
Cells perform general functions _
1) Maintain integrity and shape of cell(dep. on plasma membrane and internal contents)
2)obtain nutrients and form chemical building blocks (harvest energy for survival)
3)Dispose of wastes (avoid accumulation that could disrupt cellular activities
Note: some are capable of cell division(make more cells of the same type)…help maintain tissue by providing cells for new growth and replacing dead cells
The Plasma membrane is a _(4)
1) fluid mixture composed of equal parts (lipid and protein by weight)
2)regulates movement of most substances in and out of cell
3)contains several different types of lipids like:
phospholipids, cholesterol, glycolipids
4)establishes and maintains electrochemical gradient
What are the different types of lipids within the plasma membrane _(3)
1)Phospholipids,
2)cholesterol
3)glycolipids
What are the two types of membrane proteins _
1) Integral
2)Peripheral(they don’t go all the way across)
Membrane proteins are/do _(3)
1) half of plasma membrane by weight
2)float and move in fluid bilayer
3) performs most of the membrane functions
What are the six categories of functional proteins _
1)transport proteins (regulate the movement of substances across the membrane)
2)Cell surface receptors (bind molecules called ligands
3) Identity markers (communicate to other cells that they belong to the body…they also distinguish healthy cells from cells to be destroyed
4)enzymes (may be attached to either internal or external surface of a cell…catalyze chemical reactions)
5)anchoring sites (secure cytoskeleton to plasma membrane
6)cell-adhesion proteins(perform cell-to-cell attachments
Membrane transport is _(1)
The process of obtaining and eliminating substance across the plasma membrane
The two types of membrane transport are _
1)Passive processes(don’t require energy…dependent on substances moving down concentration gradient)
2)Active processes(require energy…substances must be moved up its concentration gradient…membrane bound vesicle must be released(vesicular transport)
What are the two types of passive transport _
1)Diffusion
2)Osmosis
Diffusion is _(2)
1)the net movement of ions or molecules from area of greater concentration to area of lesser concentration (down the concentration. gradient)
2)its influenced by temperature(increase temp. and you increase the kinetic energy and rate of diffusion)
Simple diffusion _(4)
1) molecules that move unassisted between phospholipid molecules
2) small and nonpolar solutes
3)not regulated by plasma membrane
4)movement dependent on concentration gradient(moves as long as gradient exists
Facilitated diffusion _
1)transport process for small charged or polar solute(requires assistance from plasma membrane proteins