Cytology Cell Structure & Function – the study of Objective: C1 - Summarize the principles of the cell theory, compare & contrast prokaryotic & eukaryotic cells, and analyze the levels of organization in biological systems

Discovering the Cell Robert Hooke – used a microscope to study cork coined the term “cell” Anton van Leeuwenhoek – first person to record looking at water under a microscope – a direct result of his work was… Chp. 7-1 Life is Cellular

I. Introduction to the Cell A. Cell Theory – All organisms are made up of one or more cells. – Cells are the basic unit of structure & function in organisms. – All cells come from preexisting cells.

B. Cells differ in size, shape, & organization – Cell Size Small cells function more efficiently than large cells. Large cells cannot function efficiently in the transport of materials & waste into and out of the cell.

B. Cells differ in size, shape, & organization. – Cell Shape The shape of the cell depends on its function. Cell Specialization – separate roles for each type of cell in multicellular organisms

– Most cells contain a variety of membrane bound ORGANELLES - cell parts that PERFORM SPECIFIC FUNCTIONS FOR THE CELL C. Internal Organization Nucleus Chloroplast Golgi Body Mitochondria

– NUCLEUS – contains the cell’s genetic information – controls the activities of the cell – Whether a cell has or does not have a NUCLEUS is important for classifying cells.

II. Prokaryotes Vs. Eukaryotes EUKARYOTES – ORGANISMS WHOSE CELL CONTAIN a NUCLEUS AND membrane-bound ORGANELLES – Most are multicellular; some are unicellular – Examples: Animals, Plants, Fungi, Protists

II. Prokaryotes Vs. Eukaryotes PROKARYOTES – ORGANISMS WHOSE CELLS LACK A NUCLEUS AND membrane-bound ORGANELLES – Have ribosomes (they are not membrane-bound) – Smaller than Eukaryotes – All are UNICELLULAR ORGANISMS – Example: Bacteria (it is the only example) If it’s a prokaryote, it is always a bacteria cell. If it is a bacteria cell, then it’s prokaryote.

Note: The difference between Prokaryotes and Eukaryotes is such an important distinction that they are placed in separate Kingdoms.

Prokaryotes Vs. Eukaryotes Size

Etymology Cytology: cyto-, -cyte, -cytic (Gk. KUTOS, cell) + - logy (LOGOS, word; hence the study of) Cell: (L. CELLAE, chambers) Eukaryotic: eu- (Gk. EU-, good or true) + -karyotic (KARUOTIS, with a central part/ nucleus)

Levels of Organization in Multicellular Organisms Individual cells → Tissues → Organs → Organ systems