AP Biology Final Exam Study Guide
Final Exam will cover Chapters 5, 6, and 7
Chapter 5
The Molecules of Life
• Carbohydrates
• Lipids (fats)
• Proteins
• Nucleic Acids
Macromolecules are:
• Carbohydrates
• Proteins
• Nucleic Acids
• Proteins, for example can contain thousands of atoms
• Can have a mass of over 100,000 daltons
• Now that’s
• MACRO!
POLYMERS (poly=many, meris=many parts)
• This is because they are ‘chain like’ and have many parts to them buildings blocks that make up
polymers are called: MONOMERS
• How do monomers connect to form polymers?
• Two molecules become covalently bonded to each other through a loss of a water molecule
• This is called: condensation reaction
• Specifically: dehydration reaction
Enzymes facilitate the dehydration
• Enzymes in general speed up chemical reactions in cells (for example, enzymes also break the
bonds in DNA during cell division
When polymers get broken back down into monomers, we call this process
• HYDROLYSIS (to break using water)
• This is because in order to break them down, we need to add water (H2O)
Carbohydrates (various forms
Disaccharides
Polysaccharides – polymers composed of many sugar building blocks
Cellular respiration: Cells extract energy in a series of reactions made possible by glucose
Disaccharide consists of two monosaccharides joined by glycosidic linkage.
Glycosidic linkage: simply – the dehydration reaction formed by the molecules forming a covalent bond.
Polysaccharides – macromolecules (a few hundred to a few thousand monosaccharides joined by
glycosidic linkages.
Serve as structures and building material for cells and organisms
 Glycogen – A polymer of glucose
 Animals (including humans and other vertebrates) store glycogen in liver and muscle cells
 Hydrolysis in these cells release glucose when the demand for sugar increases
 Glycogen is stored; but not for long
 In humans, glycogen is depleted in about a day unless it is replenished.
 Gives the animal much needed fuel when none other is available.
How would this be a concern for people on a low-carb diet
Lipids
 Fats are not polymers
 Assembled by dehydration reaction
 3 fatty acid molecules each join to a glycerol by an ester linkage = a fat = triacylglycerol
Phospholipids
Steroids
Amino Acids
Chapter 6
Organelles of the cells and their functions
Mitochondria and Chloroplasts
Peroxisomes
Cytoskeleton
Motor proteins
Microtubules
Cell walls of plants
Pectin
Wood
Middle lamella
Extracellular Matrix-Animal Cells
Collagen
ECM-Fibroconectin/Integrin
Cell Walls – Plasmodesmata
Chapter 7
Cellular Membranes
Fluid mosaics of lipids and proteins
The cell membrane sandwich model
Membrane proteins
Facilitated Diffusion: Passive Transport Aided By Proteins
 Kidney cells have a lot of water channel proteins (aquaporins) – they allow water to pass
through the membrane
 Ion channels : function as gated channels
 Open and close in response to a stimulus
 All cells have voltages across their plasma membranes
 Voltage is “electrical potential energy”
 Cytoplasm = negative charge
 Voltage across a membrane = membrane potential
 Membrane potential = acts like a battery
 Two forces/actions drive ions across a membrane:
 Chemical
 Electrical
 Electrochemical gradient
 Electrogenic pump: a transport protein that generates voltage across a membrane
 In animal cells = sodium-potassium pump
 In plant cells = proton pump
 These store energy that can be tapped for celllular work
 Proton gradients in the cell is ATP during cellular respiration

Cotransport – involves a single ATP powered pump that transports a specific solute and
indirectly drives the active transport of several other solutes in a mechanism
LABS
Cells: leaves, flowers, ID of organelles
Polymers