Cells and Cellular Transport Ch 7 Part 1
Characteristics of Life All Living things, known as organisms, share the following characteristics: 1. Cells 2. Response to Stimuli 3. Growth 4. Homeostasis 5. Reproduction 6. Metabolism 7. Adaptation.
Characteristics of Life cont. Living things also carry out life processes which non-living things cannot carry out. 1. Nutrition 2. Digestion 3. Absorption 4. Transport 5. Biosynthesis 6. Secretion 7. Respiration 8. Excretion 9. Response 10. Reproduction 11. Photosynthesis
Life is Cellular One of the first people to use a microscope to study nature was Anton Van Leeuwenhoek English physicist Robert Hooke is credited with the name “cells” Scientist Schleiden and Schwann are credited with the early parts of the Cell Theory
The Cell Theory 1. All living things are composed of cells 2. Cells are the basic units of structure and function in living things 3. New cells are produced from existing cells
Cell Organization Prokaryotic vs. Eukaryotic There are 2 basic types of cells: Prokaryotic and Eukaryotic Prokaryotic Cells: NO TRUE NUCLEUS No membrane bound organelles Bacteria Eukaryotic Cells: Has a nucleus surrounded by a nuclear membrane Plant and Animal Cells
Prokaryote vs Eukaryote
Cell Organization: Plants vs. Animals Plant Cells Cell wall Chloroplast Contain larger vacuoles Animal Cells centrioles
The Cell Membrane The main purpose of the cell membrane is to regulate the movement of materials into and out of the cell. Semi-permeable: meaning that only certain substances can go through
The Cell Membrane cont. The cell membrane is composed of a phospho-lipid bilayer = 2 layers of lipids Each layer consist of: Phosphate group attached to 2 fatty acid tails Phosphate heads make up the outside while the fatty acid tails are composed toward the inside Proteins are embedded within the bilayer to help transport substances into and out of the cell.
Cellular Transport Passive Transport: does NOT require energy Molecules move from an area of high concentration to an area of low concentration 1. Diffusion: substances move directly through the cell membrane (particles such as oxygen) 2. Facilitated Diffusion: uses channel proteins to move a substance through the cell membrane 3. Osmosis: The movement of WATER from an area of high water concentration to an area of low water concentration Can occur in either direction
Cellular Transport Osmosis https://www.youtube.com/watch?v=6MWl3DCa2uM Solution Concentrations: (Look at concentration of solute outside the cell) Hypotonic: solution has lower concentration of solute---higher concentration of water Cell Swells Hypertonic: solution has a higher concentration of dissolved solute---lower concentration of water Cell Shrinks Isotonic: net concentration of dissolved solutes are the same inside and outside of the cell. Cell remains the same
Cell Transport Active Transport: Requires energy Movement of substances from an area of low concentration to an area of high concentration Occurs against the concentration gradient 1. Exocytosis: removes materials from the cell 2. Endocytosis: Brings materials into the cell Phagocytosis-cellular “eating” Pinocytosis-cellular “drinking” https://www.youtube.com/watch?v=DuDmvlbpjHQ