Post on 04-Jan-2016
CellsUnit 4
The Cell Theory
All organisms are composed of one or more cells.
7.1 Cell Discovery and Theory
Cellular Structure and Function
The cell is the basic unit of structure and organization of organisms.
Chapter 7
All cells come from preexisting cells.
Cellular Structure and Function
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
7.1 Cell Discovery and Theory
Chapter 7
Electron Microscopes
Cellular Structure and Function
Utilizes magnets to aim a beam of electronsto produce an image
Magnifies images up to 500,000 times the actual size
9560x
7.1 Cell Discovery and Theory
Chapter 7
Prokaryotic Cell
Simple structure
Cellular Structure and Function
Contains a plasma membrane
Does not contain membrane-bound organelles 11,000x
7.1 Cell Discovery and Theory
Chapter 7
Eukaryotic Cell
More complex structure
Cellular Structure and Function
Contains a plasma membrane
Contains membrane-bound organelles
400x
7.1 Cell Discovery and Theory
Chapter 7
Plasma (Cell) MembraneThin, flexible boundary between the
cell and its environment
7.2 The Plasma Membrane
Cellular Structure and Function
Allows nutrients into the cellAllows waste to leave the cell
Chapter 7
Selective Permeability
Cellular Structure and Function
The plasma membrane controls the movement ofsubstances into and out of the cell.
7.2 The Plasma Membrane
Chapter 7
The plasma membrane is composed of the phospholipid bilayer.
Cellular Structure and Function
A phospholipid means:a glycerol backbonetwo fatty acid chainsa phosphate group.
7.2 The Plasma Membrane
Chapter 7
Fluid Mosaic Model
Cellular Structure and Function
The phospholipid bilayer allows other molecules to “float” in the membrane.
Other ComponentsProteinsCholesterolCarbohydrates
7.2 The Plasma Membrane
Chapter 7
Proteins
Cellular Structure and Function
Transmit signals inside the cell Act as a support structure Provide pathways for larger substances to enter
and leave the cell
7.2 The Plasma Membrane
Chapter 7
Cholesterol
Cellular Structure and Function
Prevents fatty acid tails from sticking together
7.2 The Plasma Membrane
Chapter 7
Carbohydrates
Cellular Structure and Function
Identify chemical signals
7.2 The Plasma Membrane
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
Chapter 7
CiliaShort, numerous
projections that look like hairs
Cellular Structure and Function
FlagellaLonger and less
numerous than cilia
Create movement with a whiplike motion
400x
26,367x
7.3 Structures and Organelles
Chapter 7
Passive Transport
Movement of particles across the cell membrane without using energy
7.4 Cellular Transport
Cellular Structure and Function
Three Modes of Passive Transport
Diffusion Facilitated Diffusion Osmosis
Chapter 7
DiffusionMovement of particles from an area of high
concentration to an area of lower concentration
Cellular Structure and Function
Initial ConditionsDiffusion
Low High
High Low
7.4 Cellular Transport
Chapter 7
Diffusion is controlled by
Cellular Structure and Function
Temperature PressureConcentration
Dynamic EquilibriumWhen diffusion of material into the cell
equals diffusion of material out of the cell
7.4 Cellular Transport
Chapter 7
Diffusion in a Cell
Cellular Structure and Function
7.4 Cellular Transport
Chapter 7
Facilitated Diffusion
Cellular Structure and Function
Movement of materials across the plasma membrane using proteins
7.4 Cellular Transport
Chapter 7
Cellular Structure and Function
Carrier ProteinsChannel Proteins
7.4 Cellular Transport
Chapter 7
Osmosis
Cellular Structure and Function
Diffusion of water across a selectively permeable membrane
Three Types of Solutions
Isotonic Hypotonic Hypertonic
7.4 Cellular Transport
Chapter 7
Blood CellPlant Cell
Isotonic Solution
Cellular Structure and Function
Water and dissolved substances diffuse into and out of the cell at the same rate.
11,397x
7.4 Cellular Transport
Chapter 7
Blood Cell
Hypotonic Solution
Cellular Structure and Function
Solute concentration is higher inside the cell.
Water diffuses into the cell.
Plant Cell
13,000x
7.4 Cellular Transport
Chapter 7
BLOWS UP the cell.
Plant Cell
Hypertonic Solution
Cellular Structure and Function
Solute concentration is higher outside the cell.
Water diffuses out of the cell.
Blood Cell
13,000x
7.4 Cellular Transport
Chapter 7
SHRINKS the cell.
Active Transport
Cellular Structure and Function
Movement of particles across the cell membrane using energy
Active Transport Using Carrier Proteins
7.4 Cellular Transport
Chapter 7
Cellular Structure and Function
Endocytosis
Process by which the cell surrounds and takes particles into the cell
Exocytosis
Secretion of material out of the plasma membrane
7.4 Cellular Transport
Chapter 7
Transformation of Energy
Energy is the ability to do work.
8.1 How Organisms Obtain Energy
Cellular Energy
Thermodynamics is the study of the flow and transformation of energy in the universe.
Chapter 8
Metabolism
All of the chemical reactions in a cell
8.1 How Organisms Obtain Energy
Cellular Energy
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
Chapter 8
ATP: The Unit of Cellular Energy
ATP releases energy when the bond between the second and third phosphate groups is broken.
8.1 How Organisms Obtain Energy
Cellular EnergyChapter 8
Overview of Photosynthesis
Photosynthesis occurs in two phases.
Cellular Energy
Light-dependent reactions
Light-independent reactions
8.2 Photosynthesis
Chapter 8
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
The absorption of light is the first step in photosynthesis.
Cellular Energy
Chloroplasts capture light energy.
8.2 Photosynthesis
Chapter 8
Reactions of PhotosynthesisLight 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
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.
Chapter 8
Light independent reactionsThe 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
Organisms obtain energy in a process called cellular respiration.
8.3 Cellular Respiration
Cellular Energy
The equation for cellular respiration is the opposite of the equation for photosynthesis.
Chapter 8
(Glucose) + (oxygen)---->(carbon dioxide) + (water) + energy* (ATP)
GlucoseGlycolysis
Cytoplasm
Pyruvic acid
Electrons carried in NADH
Krebs Cycle
Electrons carried in
NADH and FADH2 Electron
Transport Chain
Mitochondrion
Overview of Cellular Respiration
Mitochondrion
8.3 Cellular Respiration
Cellular Energy
Cellular respiration occurs in 3 parts.
Glycolysis
Kreb’s Cycle
Chapter 8
Electron Transport Chain
Step 1: Glycolysis
Glucose is broken down in the cytoplasm by glycolysis (splitting glucose).
Occurs in the cytoplasm
Forms 2 pyruvate from 1 glucose
8.3 Cellular Respiration
Cellular Energy
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
Chapter 8
Step 2: Krebs Cycle
Glycolysis has a net result of two ATP and two pyruvate.
8.3 Cellular Respiration
Cellular Energy
The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.
Occurs in the mitochondria
Chapter 8
8.3 Cellular Respiration
Cellular Energy
The net yield from the Krebs cycle is 6 CO2 molecules2 ATP8 NADH2 FADH2.
Chapter 8
8.3 Cellular Respiration
Cellular Energy
Step 3: Electron Transport
Final step in the breakdown of glucose
Point at which ATP is produced
Produces 24 ATP
Chapter 8
Summary FlowchartSection 9-2
Glucose(C6H1206)
+Oxygen
(02)
GlycolysisKrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
Cellular Respiration
8.3 Cellular Respiration
Cellular Energy
Anaerobic Respiration
The anaerobic pathway that follows glycolysis
Two main types:
Lactic acid fermentation
Alcohol fermentation
Glucose
Glycolysis Krebs cycle
Electrontransport
Fermentation (without oxygen)
Alcohol or lactic acid
Chemical PathwaysSection 9-1
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