Characteristics of Biotic Factors Made of cells. Consist of levels of organization (cell, tissue, organ, organ system) Respond and adapt to their environment Grow and develop Reproduce - The production of offspring that are similar to the parents. Use energy. Undergo chemical reactions (metabolism) Movement. Maintain Homeostasis

Cell Theory 1.All living things are made up of cells. 2.Basic unit of structure and function of all living things. 3.Cells come from preexisting cells through cell division. cell

Cell History Robert Hooke –1 st to study the structure of the cell (cork) in 1665 (English) Anton van Leeuwenhoek – Created simple microscopes & discovered bacteria (Dutch ) Schleiden and Schwann –1830’s plant & animals are made of cells (German ) Francesco Redi - Italian scientist mid- 1600s attempt Louis Pasteur - French mid-1800’s spontaneous generation

Cell Structure & Function

Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria

Fibroblasts Erythrocytes Epithelial cells (d) Cell that fights disease Nerve cell Fat cell Sperm (a) Cells that connect body parts, form linings, or transport gases (c) Cell that stores nutrients (b) Cells that move organs and body parts (e) Cell that gathers information and control body functions (f) Cell of reproduction Skeletal Muscle cell Smooth muscle cells Macrophage Over 200 different types of human cells

Generalized Cell All cells have some common structures and functions Human cells have three basic parts: –Plasma membrane—flexible outer boundary –Cytoplasm—intracellular fluid containing organelles –Nucleus—control center

Prokaryotic CellsEukaryotic Cells ~ 1/10 the size of eukaryotic cells Large compared to prokaryotic cells Nuclear area not membrane bound called the nucleoid Membrane bound nucleus w/ a nucleolus Single circular DNAMany chromosomes w/ linear DNA No membrane bound organelles MB: Golgi, lysosomes, ER, peroxisomes, mitochondria

Prokaryotic and Eukaryotic Cells Similarities Both have ribosomes and cytoplasm Both require a supply of energy Both have DNA as their genetic material Both are covered by a plasma (cell) membrane Both are made from the same basic chemicals: carbohydrates, proteins, nucleic acid, minerals, fats and vitamins. Both regulate the flow of the nutrients and wastes that enter and leave them

An organism whose cells lack a true nucleus and Some other cell structures. Prokaryotic Do not have structures surrounded by membranes Few internal structures EX: Bacteria Unicellular = one Celled

Eukaryotic Cell - plant Multicellular = Many cells

Eukaryotic Cell - animal Multicellular = Many cells

Cell Parts Organelles – Small cell structures

Surrounding the Cell

Cell Membrane All cells contain a cell membrane Controls movement in and out of the cell Double layer

Cell Wall a rigid layer of nonliving material that surrounds the cells of plants and some other organisms. The outermost structure of the cell Most commonly found in plant cells & bacteria Supports & protects cells

Inside the Cell

Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA

Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics A rod-shaped cellular structure made of condensed chromatin

Nucleolus Inside nucleus Create ribosomes Contains RNA to build proteins

Cytoplasm Gel-like mixture – 80% water Located between the nucleus and cell membrane Many organelles found suspended within the cytoplasm Cyto = cell Plasm = to form or mold

Endoplasmic Reticulum Transport system - Moves materials to Golgi Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface

Ribosomes Make proteins Each cell contains thousands - found on ER & floating throughout the cytoplasm

Mitochondria Produces energy through chemical reactions – THE POWERHOUSE OF THE CELL Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates

Golgi Bodies Sorts, modifies, stores, packages & distribute materials Move materials within & out of the cell

Lysosome Transports undigested material to cell membrane for removal Contain digestive enzymes – break down old cell parts, cells, bacteria, and viruses Cell breaks down if lysosome explodes

Vacuoles Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain shape

Chloroplast Usually found in plant cells Contains green chlorophyll Where photosynthesis takes place