Structure and Function of the Cell CH. 7

Introduction A cell is the smallest unit that can carry on the processes of life. B. A unicellular organism is a complete living thing that is only one cell. EX: paramecium, amoeba C. A multicellular organism is a living thing that consists of more than one cell. EX: human, buttercup

Discovery of the Cell Development and refinement of magnifying lenses and light microscopes made the observation and description of microscopic organisms and living cells possible.

Discovery of the Cell Began in the 1600's A. Robert Hooke 1. Cut a thin slice of cork and observed it with a microscope 2. Observed "little Boxes" that reminded him of the small rooms where monks lived, so he called them cells. (He observed dead cells)

Discovery of the Cell B. Anton von Leeuwenhoek 1. The first person to observe living cells. 2. He was a microscope maker

Discovery of the Cell C. Led to the CELL THEORY 1. All living things are composed of one or more cells. 2. Cells are organisms' basic units of structure and function. 3. Cells come only from pre-existing cells, by cell reproduction.

Cell Diversity Not all cells are alike, even within the same organism Size Range from 2 m (nerve cells of a giraffe's leg) to 0.2 micrometers (some bacteria)) Shape Most are roughly cuboidal or spherical Some change shape (white blood cells) Internal organization Some have membrane-bound organelles and nuclei, some do not.

Prokaryotic and Eukaryotic Cells Earth's 1st cells were prokaryotic Prokaryotic cells exist in two major forms: Eubacteria Archaebacteria Prokaryotes are the Earth's most abundant inhabitants. They can survive in a wide range of environments and obtain energy in a variety of ways. Eukaryotes arose from prokaryotes and developed into lager more complex organism from single-celled Protista to multi-cellular fungi, plants and animals

Prokaryotic vs Eurkaryotic Cell

Differences between Eukaryotes and Prokaryotes 0.1 micrometer (m)-10 m 10 m-100 m genetic material NOT surrounded by a nuclear membrane (NO NUCLEUS) genetic material surrounded by a nuclear membrane (HAVE A NUCLEUS) NO membrane bound organelles HAVE membrane bound organelles (mitochondria or chloroplasts)

Parts of a Cell The Cell membrane separates the cell from its external environment. made of lipids and proteins lipids are waterproof proteins allow food in and waste out selectively permeable (semipermeable )- only allows some molecules in and out of the cell. It flows- it is called the FLUID-MOSAIC MODEL

Parts of a Cell B. The Cytoplasm is a thick salty fluid that protects the organelles. 1. It also flows: Cytoplasmic streaming

Parts of a Cell C. There are 8 organelles ("little organs") present in Eukaryotes. Ribosomes Endoplasmic Reticulum Golgi apparatus Mitochondria Lysosomes Nucleus Plastids Vacuoles

Parts of a Cell D. Ribosomes: site of protein synthesis. Most numerous organelle Ribosomes floating freely make proteins for the cell Ribosomes attached to ER make proteins for export to other cells.

Parts of a Cell E. The Endoplasmic Reticulum (ER): a system of folded sacs and tunnels through which products made by the cell are transported. Rough ER is covered with ribosomes Smooth ER has few or no ribosomes. It is an intracellular highway.

Parts of a Cell F. Golgi Apparatus: Cell products are packaged for export

Parts of a Cell G. Mitochondria: The powerhouse ATP is formed for later use. Usually large Identified by internal folds Muscle cells have many Mitochondria Mitochondria have their own DNA They might have evolved from Prokaryotes living Symbiotically in Eukaryotes many millions of years ago.

Parts of a Cell H. Lysosomes contain digestive enzymes. In animal, fungus, and carnivorous plant cells. They digest food, bacteria, and old cell parts

Parts of a Cell Microtubules and Microfilaments support "skeleton" of the cells. Special MT's called spindle fibers move DNA during cell division

Parts of a Cell A paramecium has 17,000 cilia for locomotion J. Cilia and Flagella: locomotion (movement) and feeding. A paramecium has 17,000 cilia for locomotion A sperm's tail is the most familiar flagellum

Parts of a Cell K. The Nucleus: contains the genes (DNA) of the cell. Site where RNA is made. It is surrounded by a double membrane (nuclear envelope) perforated with pores. Contains Chromosomes, which are rod shaped structures containing DNA and protein. The Nucleolus is also found in the nucleus. It produces ribosomes. The nucleus controls the cell's functioning.

Parts of a Cell L. Vacuoles and Plastids: only in plants Vacuoles: storage areas for enzymes and waste products A Vacuole can take up 90 % of the cell. Plastids store food and pigment needed by the plant. Chloroplasts store chlorophyll (green) (PHOTOSYNTHESIS) Leucoplasts store starches, proteins, and lipids. Chromoplasts synthesize and store pigments which function in trapping sunlight

Parts of a Cell M. Plant cells are also identified by their cubic shape from the Cell Wall Supports and protects cell.

How are we going to remember all of these parts? Well you can always try this… http://www.youtube.com/watch?v=jqUhWDp73bM