Cell Structure and Function Chapter 7 Cell Structure and Function

Parts of the Microscope Microscope parts & their functions

Copyright Pearson Prentice Hall 7-1 Life Is Cellular Photo Credit: © Quest/Science Photo Library/Photo Researchers, Inc. Copyright Pearson Prentice Hall 3

The Discovery of the Cell Early Microscopes In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.” Cells are the basic units of life. Copyright Pearson Prentice Hall 4

The Cell Theory In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells. These discoveries led to the cell theory.

The Cell Theory The cell theory states: All living things are composed of cells. Cells are the basic units of structure and function in living things. New cells are produced from existing cells.

Basic Cell Structures All cells have a cell membrane. It is a thin, flexible barrier around the cell. Many cells also have a strong layer around the cell membrane called a cell wall. Some cells also have a nucleus, a large structure that contains the cell’s genetic material and controls cell activities. The material inside the cell, not including the nucleus, is called the cytoplasm

Cell Types Biologists divide cells into two categories: eukaryotes and prokaryotes

Characteristics of Prokaryotes Similarities between Prokaryotes and Eukaryotes Characteristics of Eukaryotes

Prokaryotes - smaller and simple than eukaryotes have cell membranes and cytoplasm No nucleus Contain DNA Contains all bacteria Examples: E.coli, MRSA, causes Strep Throat

Eukaryotes contain nuclei Contain DNA Have cell membrane, cytoplasm Specialized structures called organelles Many are large and multicellular organisms Grouped into either plant cells or animal cells

Prokaryotes vs. Eukaryotes SMARTboard

Animal Cell Labeling

Plant Cell Labeling

7-2 Cell Structures A Comparison of Cells   Structure Prokaryotic Cell Eukaryotic Cell Plants Animals Cell membrane Cell wall Nucleus Ribosomes Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Chloroplasts Cytoskeleton 7-2 Cell Structures -Organelle – “little organs” in the cell with specialized functions - Why does a cell compare to a factory? Use page 197 to find out. Write your answer in the space provided.

Cell Structure Cell Type Found In Function Extra Info. Cell Wall

Cell Structure Cell Type Found In Function Extra Info. Nucleus Nucleolus Nuclear Envelope Chromosomes Chromatin

Cell Structure Cell Type Found In Function Extra Info. Vacuoles Vesicles

Cell Structure Cell Type Found In Function Extra Info. Lysosomes Cytoskeleton Microtubule Microfilament Centriole

Cell Structure Cell Type Found In Function Extra Info. Ribosomes Endoplasmic Reticulum (Smooth and Rough)

Cell Structure Cell Type Found In Function Extra Info. Golgi Apparatus

Cell Structure Cell Type Found In Function Picture Extra Info. Chloroplast Mitochondria

Cell Structure Cell Type Found In Function Extra Info. Cell Wall Cell Membrane

Page 200-201: Use the picture to create a flow chart of how proteins are made in the cell Where are proteins assembled? Where is the synthesis (making) of membrane proteins completed? How are proteins transported to the golgi apparatus? What happens to proteins leaving the golgi apparatus?

Cell Structure and Function Matching

Building Proteins: SMARTboard

Cell Membrane Structure All cells are surrounded, flexible barrier known as the cell membrane. Many cells also produce a strong supporting layer around the membrane known as a cell wall

Cell Membrane Cell membrane is also known as lipid bilayer The cell membrane regulates what enters and leaves the cell and also provides protection and support.

Measuring Concentrations A solution is mixture of two or more substances. The substances dissolved in the solution are called the solutes The concentartion of a solutions is the mass of solute in a given volume, or mass/volume.

7-3 Cell Transport Passive Transport – movement of molecules across the cell membrane without the use of energy Examples include: Diffusion Facilitated Diffusion Osmosis

Diffusion Particles in a solution tend to move from an area where they are more concentrated to an area where they are less concentrated. This process is called diffusion. When the concentration of the solute is the same throughout a system, the system has reached equilibrium.

Osmosis: An example of Facilitated Diffusion Osmosis is the diffusion of water through a selectively permeable membrane from higher concentration to lower concentration Water tends to diffuse from a higher concentration to Lower concentration Water moves through the cell Membrane through proteins Called aquaporins

Osmosis Water tends to diffuse from a highly concentrated region to a less concentrated region. If you compare two solutions, three terms can be used to describe the concentrations: hypertonic (“above strength”). hypotonic (“below strength”). isotonic (”same strength”)

Osmosis If you place a cell in a hypertonic solution, the the concentration of dissolved materials is greater OUT of the cell, therefore the cell will LOSE water, and will SHRINK If you place a cell in a hypotonic solution, the concentration of dissolved materials is greater IN the cell, therefore the cell will GAIN water, and will EXPAND If you place a cell in an isotonic solution, the concentration of dissolved materials is EQUAL in and out of the cell, and NOTHING will happen to the cell

Facilitated diffusion Glucose molecules Movement of molecules with the help of protein channels in the cell membrane. Molecules move from higher concentration to lower concentration Protein channel

Active Transport Sometimes cells move materials in the opposite direction from which the materials would normally move—that is against a concentration difference. This process is known as active transport. Active transport requires energy.

Active Transport Endocytosis and Exocytosis Endocytosis is the process of taking material into the cell. Two examples of endocytosis are: phagocytosis pinocytosis During exocytosis, materials are forced out of the cell.

Videos Facilitated Diffusion Active Transport

Solution A Solution B

7-4 The Diversity of Cellular Life Unicellular Organisms – organisms with only one cell include prokaryotes – bacteria include eukaryotes – some algae, yeast

Multicellular organisms – orgnasisms with more than one cell have cell specialization – each cell has their own role within the organism

Levels of Organization The levels of organization in a multicellular organism are individual cells, tissues, organs and organ systems