Cells

All organisms are composed of one or more cells. Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory The Cell Theory All organisms are composed of one or more cells. The cell is the basic unit of structure and organization of organisms. All cells come from preexisting cells.

The Wacky History of Cell Theory

Magnifies images up to 1,000 times the actual size Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Light Microscopes Utilizes a series of glass lenses and visible light to magnify an image Magnifies images up to 1,000 times the actual size

Utilizes magnets to aim a beam of electrons to produce an image Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Electron Microscopes Utilizes magnets to aim a beam of electrons to produce an image Magnifies images up to 500,000 times the actual size 9560x

Contains a plasma membrane Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Prokaryotic Cell Simple structure Contains a plasma membrane Does not contain membrane-bound organelles or a nucleus Think: “PRO sounds like NO”

More complex structure Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Eukaryotic Cell More complex structure Contains a plasma membrane Contains membrane-bound organelles and a nucleus Think: “EU sounds like DO”

Plasma (Cell) Membrane Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Plasma (Cell) Membrane Thin, flexible boundary between the cell and its environment Allows nutrients into the cell Allows waste to leave the cell

Selective Permeability Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Selective Permeability The plasma membrane controls the movement of substances into and out of the cell.

The plasma membrane is composed of the phospholipid bilayer. Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane The plasma membrane is composed of the phospholipid bilayer. A phospholipid means: a glycerol backbone two fatty acid chains a phosphate group.

Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Fluid Mosaic Model The phospholipid bilayer allows other molecules to “float” in the membrane. Other Components Proteins Cholesterol Carbohydrates

Transmit signals inside the cell Act as a support structure Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Proteins Transmit signals inside the cell Act as a support structure Provide pathways for larger substances to enter and leave the cell

Prevents fatty acid tails from sticking together Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Cholesterol Prevents fatty acid tails from sticking together

Identify chemical signals Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Carbohydrates Identify chemical signals

7.3 Structures and Organelles Chapter 7 Cellular Structure and Function 7.3 Structures and Organelles

7.3 Structures and Organelles Chapter 7 Cellular Structure and Function 7.3 Structures and Organelles

Short, numerous projections that look like hairs Chapter 7 Cellular Structure and Function 7.3 Structures and Organelles Cilia Short, numerous projections that look like hairs Flagella Longer and less numerous than cilia Creates movement with a whip-like motion

Three Modes of Passive Transport Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Movement of particles across the cell membrane without using energy (Goes with the flow. Three Modes of Passive Transport Diffusion Facilitated Diffusion Osmosis

Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Diffusion Movement of particles from an area of high concentration to an area of lower concentration Diffusion Initial Conditions Low High High Low

Diffusion is controlled by Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Diffusion is controlled by Temperature Pressure Concentration Dynamic Equilibrium When diffusion of material into the cell equals diffusion of material out of the cell

Diffusion in a Cell 7.4 Cellular Transport Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Diffusion in a Cell

Facilitated Diffusion Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Facilitated Diffusion Movement of materials across the plasma membrane using proteins

Channel Proteins Carrier Proteins 7.4 Cellular Transport Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Channel Proteins Carrier Proteins

Diffusion of water across a selectively permeable membrane Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Osmosis Diffusion of water across a selectively permeable membrane Three Types of Solutions Isotonic Hypotonic Hypertonic

Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Isotonic Solution Water and dissolved substances diffuse into and out of the cell at the same rate. Cell stays the same. Plant Cell Blood Cell 11,397x

Solute concentration is higher inside the cell. Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Hypotonic Solution Solute concentration is higher inside the cell. Water diffuses into the cell. BLOWS UP the cell. Blood Cell Plant Cell 13,000x

Solute concentration is higher outside the cell. Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Hypertonic Solution Solute concentration is higher outside the cell. Water diffuses out of the cell. SHRINKS the cell. Blood Cell Plant Cell 13,000x

Active Transport Using Carrier Proteins Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport Movement of particles across the cell membrane using energy Active Transport Using Carrier Proteins

Process by which the cell surrounds and takes particles into the cell Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Endocytosis Process by which the cell surrounds and takes particles into the cell Exocytosis Secretion of material out of the plasma membrane

Transformation of Energy Chapter 8 Cellular Energy 8.1 How Organisms Obtain Energy Transformation of Energy Energy is the ability to do work. Thermodynamics is the study of the flow and transformation of energy in the universe.

All of the chemical reactions in a cell Chapter 8 Cellular Energy 8.1 How Organisms Obtain Energy Metabolism All of the chemical reactions in a cell Photosynthesis—light energy from the Sun is converted to chemical energy for use by the cell Cellular respiration—organic molecules are broken down to release energy for use by the cell

ATP: The Unit of Cellular Energy Chapter 8 Cellular Energy 8.1 How Organisms Obtain Energy ATP: The Unit of Cellular Energy ATP releases energy when the bond between the second and third phosphate groups is broken.

Overview of Photosynthesis Chapter 8 Cellular Energy 8.2 Photosynthesis Overview of Photosynthesis Photosynthesis occurs in two phases. Light-dependent reactions Light-independent reactions

Light and pigments Photosynthesis requires light and the pigment chlorophyll The green pigment is the wavelength reflected rather than absorbed, by plants the most – so plants are green and other colors are absorbed

Phase One: Light Reactions Chapter 8 Cellular Energy 8.2 Photosynthesis Phase One: Light Reactions The absorption of light is the first step in photosynthesis. Chloroplasts capture light energy.

Reactions of Photosynthesis Light dependent reactions Grana are stacks of thylakoids in the chloroplast that contain the chlorophyll which captures sunlight Light dependent reactions take place in the thylakoids

Phase Two: The Calvin Cycle (Light-Independent) Chapter 8 Cellular Energy 8.2 Photosynthesis Phase Two: The Calvin Cycle (Light-Independent) In the second phase of photosynthesis, called the Calvin cycle, energy is stored in organic molecules such as glucose.

Light independent reactions The Calvin Cycle The Calvin cycle or light independent reactions take place in the stroma Uses ATP and NADPH from light dep. Reactions to produce high energy sugars

Overview of Cellular Respiration Chapter 8 Cellular Energy 8.3 Cellular Respiration Overview of Cellular Respiration Organisms obtain energy in a process called cellular respiration. The equation for cellular respiration is the opposite of the equation for photosynthesis. (Glucose) + (oxygen)---->(carbon dioxide) + (water) + energy* (ATP)

Overview of Cellular Respiration Mitochondrion Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Electron Transport Chain Krebs Cycle Glycolysis Mitochondrion Cytoplasm

Cellular respiration occurs in 3 parts. Chapter 8 Cellular Energy 8.3 Cellular Respiration Cellular respiration occurs in 3 parts. Glycolysis Kreb’s Cycle Electron Transport Chain

Step 1: Glycolysis 8.3 Cellular Respiration Chapter 8 Cellular Energy 8.3 Cellular Respiration Step 1: Glycolysis Glucose is broken down in the cytoplasm by glycolysis (splitting glucose). Occurs in the cytoplasm Forms 2 pyruvate from 1 glucose 2 molecules of ATP and 2 molecules of NADH are formed for each molecule of glucose that is broken down. Takes 2 ATP to start

Glycolysis has a net result of two ATP and two pyruvate. Chapter 8 Cellular Energy 8.3 Cellular Respiration Step 2: Krebs Cycle Glycolysis has a net result of two ATP and two pyruvate. The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle. Occurs in the mitochondria

The net yield from the Krebs cycle is 6 CO2 molecules 2 ATP 8 NADH Chapter 8 Cellular Energy 8.3 Cellular Respiration The net yield from the Krebs cycle is 6 CO2 molecules 2 ATP 8 NADH 2 FADH2.

Step 3: Electron Transport Chapter 8 Cellular Energy 8.3 Cellular Respiration Step 3: Electron Transport Final step in the breakdown of glucose Point at which ATP is produced Produces 32 ATP

Electron Transport Chain Section 9-2 Summary Flowchart Cellular Respiration Glucose (C6H1206) + Oxygen (02) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO2) + Water (H2O)

Anaerobic Respiration Cellular Energy 8.3 Cellular Respiration Anaerobic Respiration The anaerobic pathway that follows glycolysis Two main types: Lactic acid fermentation Alcohol fermentation

Fermentation (without oxygen) Chemical Pathways Section 9-1 Glucose Krebs cycle Electron transport Glycolysis Alcohol or lactic acid Fermentation (without oxygen)

Fermentation A process in the absence of oxygen (anaerobic) Lactic acid fermentation – NADH is converted back to NAD producing lactic acid Occurs when body can’t supply enough oxygen to the muscles during exercise = soreness, burning, fatigue