Cell Structure and Function
Review: Define the following terms. cell Cyte = Cytology - Histo = Histology - Cell - Study of cells tissue Study of tissue Units of structure and function in living things
Cells are the smallest unit that can perform all life processes Cells are the smallest unit that can perform all life processes. (units of structure and function)
The Discovery of Cells
Anton Van Leeuwenhoek Anton van Leeuwenhoek was a Dutch lens maker. He developed the first microscope and viewed living cells.
Robert Hooke Robert Hooke named cells after the cork he saw. It was dead and empty.
Schileiden - All plants are made of cells. Schwann - All animals are made of cells.
Virchow - Cells come from other cells.
The work of these men is summarized into the cell theory. All organisms are composed of cells. Cells are the basic units of structure and function. All cells come from preexisting cells. Cells contain hereditary material (DNA).
Metabolic Processes of Cells These processes occur simultaneously within all cells. nutrition - food for energy and growth digestion - breakdown of molecules by enzymes and water, hydrolysis absorption - taking in of vital substances (water, food, ions, oxygen, vitamins)
4. biosynthesis - building of new compounds 5. respiration - combining glucose and oxygen to release energy for the cell - an exchange of gases excretion - elimination of dissolved waste secretion - discharge of cellular products
8. response - reacts to a stimulus 9. movement - flow of content, contraction, locomotion 10. reproduction - sexual by combining egg and sperm to form a zygote - asexual by cellular division
Kinds of Cells
prokaryotic cells - cells without a nucleus pro = first, before karyote = nucleus
Organisms with a prokaryotic cell are called prokaryotes. ex: eubacteria – the true bacteria Archaebacteria
2. eukaryotic cells – cells with a nucleus eu = true karyote = ? Organisms with eukaryotic cells are known as eukaryotes. animals plants fungi protists
Plant Cells
Animal Cells
Cells vary in size. Most cells are too small to be seen with the naked eye.
A cell’s surface area-to-volume ratio limits the size of a cell.
3 Main Parts of Eukaryotic Cells 1. Cytoplasm between nucleus and outer membrane houses organelles semifluid with water, salts, and organic molecules Video: http://vimeo.com/26915500
ctyoplasmic streaming - moves materials throughout the cell
2. nucleus controls cellular activities transmits hereditary material
Parts of the Nucleus nuclear membrane - surrounds and has nuclear pores nucleolus – spherical body which produces ribosomes chromatin – DNA, hereditary material
3. cell membrane separates cells from surrounding fluid selectively permeable (semipermeable) regulates what enters and leaves the cell
structure - Fluid Mosaic Model double layer of phospholipids with proteins embedded
Cell Wall found in plants, algae, fungi, bacteria Rigid; protects and supports contains cellulose for structure surrounds cell membrane Cell Membrane