Cells and Cellular Transport Ch 7 Part 1
Jan 17, 2016
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 OrganizationProkaryotic 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 Osmosishttps://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