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