Chapter 8: Life’s structure and Classification Living Things

What are living things like? Organism: Any living thing Can vary in size (bacteria---gigantic oak tree----humans) Have different behaviors and food requirements

Similarities between all living things They are organized All organisms are made up of cells (the smallest unit of an organism that carries on the function of life) They grow and develop Infant—adult Organisms change as they grow (development) They respond Living things must interact with their environment Stimulus: Anything that causes some change in an organism. Response: the reaction to a stimulus-Results in movement

Similarities between all living things (continued..) They maintain homeostasis Ability of an organism to maintain proper internal conditions despite changes in the environment. They use energy All organisms require energy for everyday life functions (staying organized, carrying on activities-finding/making food) They reproduce Making their own kind Living things need to replace those individuals that die

What do living things need? A place to live Suited to their unique needs (temperature, sunlight, space etc..) Water Important functions: transporting materials within a cell and between cells. We are made up of 60-70% of water! Food sources Take in substances (protein, fats, sugars) from other animals Plants and some bacteria make their own food

What are the functions of each part of a cell? Cell Structure What are cells? What are the functions of each part of a cell? - What is the difference between unicellular and multi-cellular organisms?

A little history 1600’s : Leeuwenhoek made a simple microscopeled to types of microscopes we use today Discovered cells under microscope Robert Hooke looked at a cork and saw many empty little boxes—named them cells 1800’s: Schleiden(plant cell) and Schwann (animal cell): all living things are made up of cells Virchow: main contributor to the cell theory

The Cell Theory All organisms are made up of one or more cell The cell is the basic unit of organization in organisms Basic unit of structure and function All cells come from cells Divide to form new, identical cells

Prokaryotic vs Eukaryotic Cell Prokaryotic: only found in ONE-celled organisms Cells without membrane-bound structures Ex: Bacteria Eukaryotic: More complex internal structure Cells with membrane bound structures Ex: protists, fungi, plants and animals

Prokaryote vs Eukaryote

Cellular organization - Main structures Organelle: parts of the cell Just Plant Cell Both Plant and Animal Cell Just Animal Cell Cell wall Cell membrane Centrioles Chloroplasts Cytoplasm Cytoskeleton Nucleus Mitochondria Golgi Vacuole Endoplasmic reticulum Ribosome (Lysosome)

Cell structure Description/function Cell Membrane Protective layer surrounding every cell Regulates interactions (what goes in and out) between the cell and its environment Nutrients move in, waste moves out Cytoplasm Gelatin like substance which cells are filled with Where the cells organelles are located Most of cells life processes occur here Nucleus contains a membrane, nucleolus, and hereditary material (DNA) Control center(all cellular activities are directed here)

Eukaryotic Cell Membrane Image Bank Eukaryotic Cell Membrane

Cell structure Description/function continued Mitochondria Powerhouse of the cell-releases energy that is needed by the cell Golgi bodies Stacked flattened membranes Package material for release to the outside of the cell Vacuole Membrane-bound spaces Temporary storage of materials (stores water, waste products, food etc.)

Cell structure Description/function continued Endoplasmic reticulum (ER) Series of folded membranes Transport materials inside cell Ribosomes Make proteins Proteins: part of cell membranes and needed for chemical reactions that take place in the cytoplasm Chloroplasts (plant only) Contains chlorophyll Use light to make sugar-food and energy for plants

Cell structure/function Lysosome Break down & Recycle! Contain digestive chemicals that break down food molecules, cell wastes, worn out cell parts and viruses and bacteria that enter cell When cell dies, release chemicals to breakdown cell contents

Animal vs Plant Cell

Unicellular vs Multicellular organisms Unicellular organism: one celled organism (perform all life functions on their own) Multicellular organisms: many celled organisms (cells cannot function alone) Celltissueorganorgan systemsorganism

Image Bank Many-Celled Organism