Cell Structure and Function

1
Cell Structure and Function
2
Egg-speriment With a Cell

• Chapter Project, page 5

3
Discovering Cells

• What are cells?
• How did the invention of the microscope
  contribute to knowledge about living things?
• What is the cell theory?
• How do microscopes produce magnified images?

4
Discovering Cells

• An Overview of Cells
• Cells are the basic units of structure and
  function in living things.

5
Discovering Cells

• Cells and Structure
• Cells and Function
• Many and Small

6
Discovering Cells

• First Observation of Cells
• The invention of the microscope made it possible
  for people t discover and learn about cells.
• Microscope an instrument that makes small
  objects look larger

7
Discovering Cells

• Robert Hooke
• Anton van Leeuwenhoek

8
Development of the Cell Theory

• Schleiden, Schwann, and Virchow
• Cell Theory a widely accepted explanation of
  the relationship between cells and living things

9
Discovering Cells

• What the Cell Theory Says
• The cell theory states the following
• All living things are composed of cells.
• Cells are the basic units of structure and
  function in living things.
• All cells are produces from other cells.

10
Discovering Cells

• Light and Electron Microscopes
• Magnification and Lenses
• The lenses in light microscopes magnify an object
  by bending the light that passes through them.

11
Discovering Cells

• Compound Microscope Magnification
• Resolution
• Electron Microscopes
• Electron microscopes use a beam of electrons
  instead of light to produce a magnified image.

12
Design and Build a Microscope

• Technology Lab, pages 14, 15

13
Looking Inside Cells

• What role do the cell wall and cell membrane play
  in the cell?
• What are the functions of cell organelles?
• How are cells organized in many-celled organisms?
• How do bacterial cells differ from plant
  andanimal cells?

14
Looking Inside Cells

• Organelles tiny cell structures inside a cell
  that carry out specific functions within the cell

15
Looking Inside Cells

• Enter the Cell
• Cell Wall a rigid layer of nonliving material
  that surrounds the cells of plants and some other
  organisms
• A plants cell wall helps to protect and support
  the cell.

16
Looking Inside Cells

• Cell Membrane a cell structure that controls
  which substances can enter or leave the cell
• The cell membrane controls what substances come
  into and out of the cell.

17
Looking Inside Cells

• Sail on to the Nucleus
• Nucleus a cell structure that contains nucleic
  acids, the chemical instructions that direct all
  the cells activities
• You can think of the nucleus as the cells
  control center, directing all of the cells
  activities.

18
Looking Inside Cells

• Nuclear Envelope
• Chromatin
• Nucleolus

19
Looking Inside Cells

• Organelles in the Cytoplasm
• Mitochondria a rod-shaped cell structures that
  convert energy in food molecules to energy the
  cell can use to carry out its functions

20
Looking Inside Cells

• Mitochondria are known at the powerhouses of
  the cell because they convert energy in food
  molecules to energy the cell can use to carry out
  its functions.

21
Looking Inside Cells

• Endoplasmic Reticulum a cell structure that
  forms a maze of passageways in which proteins and
  other materials are carried from one part of the
  cell to another
• The endoplasmic reticulums passageways carry
  proteins and other materials from one part of the
  cell to another.

22
Looking Inside Cells

• Ribosomes small, grainlike bodies attached to
  some surfaces of the endoplasmic reticulum
• Ribosomes function as factories to produce
  proteins.

23
Looking Inside Cells

• Golgi Bodies a structure in a cell that looks
  like flattened sacs and tubes and functions like
  the cells mail room.
• The Golgi Bodies receive proteins and other newly
  formed materials from the endoplasmic reticulum,
  package them, and distribute them to other parts
  of the cell.

24
Looking Inside Cells

• Chloroplasts large green structures floating in
  the cytoplasm of plant cells
• Chloroplasts capture energy from sunlight and use
  it to produce food for the cell.

25
Looking Inside Cells

• Vacuoles large water-filled sacs floating in
  the cytoplasm
• Vacuole are the storage areas of cells.

26
Looking Inside Cells

• Lysosomes the cells cleanup crew
• Lysosomes are small, round structures containing
  chemicals that break down certain materials in
  the cell.

27
Looking Inside Cells

• Specialized Cells
• In many-celled organisms, cells are often
  organized into tissues, organs, and organ systems.

28
Looking Inside Cells

• Bacterial Cells
• While a bacteria cell does have a cell wall and a
  cell membrane, it does not contain a nucleus.
  The bacterial cells genetic material, which
  looks like a thick, tangled string, is found in
  the cytoplasm.

29
Chemical Compounds

• What are elements and compounds?
• What are the main kinds of organic molecules in
  living things?
• How is water important to the function of cells?

30
Chemical Compounds

• Elements and Compounds
• An element is any substance that cannot be broken
  down into simpler substances.
• When two or more elements combine chemically,
  they form a compound.

31
Chemical Compounds

• Organic and Inorganic Compounds
• Some important groups of organic compounds found
  in living things are carbohydrates, lipids,
  proteins, and nucleic acids.

32
Chemical Compounds

• Carbohydrate an energy-rich organic compound
  made of the elements carbon, hydrogen, and oxygen
• Lipids energy-rich organic compounds made of
  carbon, hydrogen, and oxygen

33
Chemical Compounds

• Proteins large organic molecules made of
  carbon, hydrogen, oxygen, nitrogen, and, in some
  cases, sulfur

34
Chemical Compounds

• Structure of Proteins
• Amino Acids the building blocks of proteins

35
Chemical Compounds

• Functions of Proteins
• Enzyme a type of protein that speeds up a
  chemical reaction in a living thing

36
Chemical Compounds

• Nucleic Acids very long organic molecules made
  of carbon, oxygen, hydrogen, nitrogen, and
  phosphorus
• DNA the genetic material that carries
  information about an organism
• RNA helps build proteins inside a cell

37
Chemical Compounds

• Water and Living Things
• Most chemical reactions within cells could not
  take place without water.

38
The Cell in Its Environment

• How do most small molecules cross the cell
  membrane?
• Why is osmosis important to cells?
• What is the difference between passive transport
  and active transport?

39
The Cell in Its Environment

• Selective Permeable some substances can pass
  through the membrane while others cannot

40
The Cell in Its Environment

• Diffusion the process by which molecules move
  from an area of higher concentration to an area
  of lower concentration
• Diffusion is the main method by which small
  molecules move across the cell membrane.

41
The Cell in Its Environment

• What Causes Diffusion?
• Diffusion of Oxygen

42
The Cell in Its Environment

• Osmosis the diffusion of water molecules
  through a selectively permeable membrane
• Because cells cannot function properly without
  adequate water, many cellular processes depend on
  osmosis.

43
The Cell in Its Environment

• Osmosis and Diffusion
• Effects of Osmosis

44
The Cell in Its Environment

• Passive Transport the movement of dissolved
  materials through a cell membrane without using
  cellular energy
• Active Transport the movement of materials
  through a cell membrane using cellular energy
• Active transport requires the cell to use its own
  energy, while passive tyrasport does not.

45
The Cell in Its Environment

• Transport Proteins
• Transport by Engulfing
• Why Cells Are Small

46
Cell Structure and Function

• Review