AP Bio 5 Reading Guide
Name the correct carbohydrate for each? Structural polysaccharide that gives cockroaches their crunch
chitin
Some people refer to this structure as three hexagons and a doghouse. What is it? -look at diagram from question 36
Cholesterol (a steroid)
What molecules make up the "rungs"?
Base pairs joined by hydrogen bonding
Most monosaccharides are some multiple of (CH2O). For example, ribose is a 5-carbon sugar with the formula C5H10O5. It is a pentose sugar. (From the root penta-, meaning five.) What is the formula of a hexose sugar?
C6H12O6
What are other examples of steroids?
vertebrate sex hormones
What two molecules make up the "uprights"?
Sugar and phosphate
What is a glycosidic linkage?
a covalent bond formed between 2 monosaccharides by a dehydration reaction.
On the figure with question 22, label the ester linkages. -look at diagram from question 22
answer on diagram from question 22
Name the correct carbohydrate for each? Structural polysaccharide that comprises plant cell walls
cellulose
Name the correct carbohydrate for each? Is a storage polysaccharide produced by vertebrates; stored in your liver
glycogen
The root words of hydrolysis will be used many times to form other words you will learn this year. What does each root word mean? -hydro: -lysis
hydro- water lysis- break
To summarize, a phospholipid has a glycerol attached to a phosphate group and two fatty acid chains. The head is hydrophilic, and the tail is hydrophobic. Now, sketch the phospholipid bilayer structure of a plasma membrane. Label the hydrophilc heads, hydrophobic tails, and location of water.
- answers is found in question 34 -water is found on the outside -hydrophilic heads are on the outside -hydrophobic tails are found on the inside
Know how to identify a dipeptide, polypeptide, and peptide bond -diagram on question 44
-answers on question 44
Level of Protein Structure: Secondary (II^0) -explanation -Alpha helix -Beta pleated sheets -Alpha example Beta example
-coils and folds resulting from hydrogen bonds between the repeating constituents of the polypeptide backbone -coils -folds -ex. protein in hair -ex. protein in silk
-What 2 monosaccharides form sucrose? -Where is sucrose found?
-glucose and fructose -table sugar
-What 2 monosaccharides form lactose? -Where is lactose found?
-glucose and galactose -milk sugar
Level of Protein Structure: Tertiary (III^0) -explanation -example
-interactions among various R groups -transthyretin polypeptid
Notice that two monomers are joined to make a polymer. Since the monomers are monosaccharides, the polymer is a disaccharide. Three disaccharides have the formula C12H22O11. What are the 3 disaccaride?
-maltose -sucrose -lactose
What is represented by R? How many are there?
-side chains of amino acids -there are 20
There are two categories of polysaccharides. Name them and give examples.
-storage (ex. glycogen, starch) -structural (ex. cellulose, chitin)
Study the figure. See if you can understand why some R groups are nonpolar, some polar, and others electrically charged (acidic or basic). If you were given an R group, could you place it in the correct group? Work on the R groups until you can see common elements in each category. *THIS IS IMPORTANT KNOW HOW TO IDENTIFY* -diagram found from question 43
-tells you how to identify and some examples on diagram from question 43
Chaperone proteins or chaperonins assist in the proper folding of proteins. Annotate this figure to explain the process. -Look at diagram from question 50 to see the steps
1. An unfolded polypeptide enters the cylinder from one end. 2. The cap attaches, causing the cylinder to change shape in such a way that it creates a hydrophilic environment for the folding of the polypeptide. 3. The cap comes off, and the properly folded protein is released.
What is a trans fat? Why should you limit them in your diet?
A trans fat is an unsaturated fat with a trans double bond; the result of the process of hydrogenating vegetable oils to prevent lipids from separating out in liquid (oil) form. Trans fats should be limited in your diet because they have been found to contribute to atherosclerosis, a cardiovascular disease caused by plaque buildup within the walls of blood vessels.
Which four are found in RNA?
Adenine, guanine, cytosine, uracil
Lipids include fats, waxes, oils, phospholipids, and steroids. What characteristic do all lipids share?
All lipids mix poorly, if at all, with water.
How do ribose and deoxyribose sugars differ?
Deoxyribose sugar lacks an oxygen atom on the second carbon in the ring
What is the difference between an aldehyde sugar and a ketone sugar?
Depending on the location of the carbonyl group, a sugar is either an aldose (aldehyde sugar) or a ketose (ketone sugar). Glucose, for example, is an aldose; fructose, an isomer of glucose, is a ketose. In aldehyde sugars, the carbonyl group is at the end of the carbon skeleton, while in the ketone sugars, the carbonyl group is within the carbon skeleton.
Here is a model of DNA, which was proposed by James Watson and Francis Crick. What is this shape called?
Double helix
Why are the "tails" hydrophobic?
The "tails" are hydrophic (avoid water) because they are hydrcarbon. hydrocarbons are hydrophobic compounds because the great majority of their bonds are relatively nonpolar carbon-to-hydrogen.
Why are many unsaturated fats liquid at room temperature?
The kinks where the cis bonds are located prevent the molecules from packing together closely enough to solidify at room temperature.
Why are the strands said to be antiparallel?
The strands are said to be antiparallel because they run in opposite 5' -> 3' directions from each other.
Draw a fatty acid chain that is eight carbons long and is unsaturated. Circle the element in your chain that makes it unsaturated, and explain what this means. (diagram from question 25)
Unsaturated fatty acids have one or more double bond, with one fewer hydrogen atom on each double bonded carbon from the carbon skeleton. This means they are liquid at room temperature.
Here is a molecule of starch, which shows 1-4 glycosidic linkages. Translate and explain this terminology in terms of carbon numbering.
When glucose forms a ring, the hydroxyl group attached to the number 1 carbon is positioned either below or above the plane of the ring. These two ring forms for glucose are called alpha and beta. In starch, all the glucose monomers are in the alpha configuration.
What is a polymer?
a long chain-like molecule, consisting of many similar or identical building blocks linked by covalent bonds.
Besides mutation, which changes the primary structure of a protein, protein structure can be changed by denaturation. Define denaturation, and give at least three ways a protein may become denatured.
a protein unravels and loses its shape because the bonds between the proteins are destroyed -change in pH -change in temp -chemical -salt concentration
What is a monomer?
a smaller molecule that serves as the building blocks of polymers.
*Know how to identify the four different types of protein structures* -Label diagram from question 46
answers found on diagram from question 46 (primary- line, secondary- folds or coils, tertiary- chunk, Quaternary- multiple chunks)
Name two saturated fats.
butter and most animal fats
Here are the three hexose sugars. Label each of them. Notice that all sugars have the same two functional groups. Name them: -Diagram in question 10 C=O __________________ -OH __________________
carbonyl group hydroxyl group
Name the correct carbohydrate for each? Glucose + ______________ form sucrose
fructose
Name the correct carbohydrate for each? Monosaccharide commonly called "fruit sugar"
fructose
Name the correct carbohydrate for each? Two monomers of this form maltose
glucose
So, as a quick review, all of the sugars in the figure above have the same chemical formula: C6H12O6. What term did you learn in Chapter 3 for compounds that have the same molecular formulas but different structural formulas?
isomers
Name the correct carbohydrate for each? "Milk sugar"
lactose
Name the correct carbohydrate for each? Malt sugar; used to brew beer
maltose
Let's look at carbohydrates, which include sugars and starches. First, what are the monomers of all carbohydrates?
monosaccharides (simple sugars)
Name two unsaturated fats.
plant fats and fish fats
Define dipeptide
polymer of 2 amino acids linked by a peptide bond
Define polypeptide
polymer of many amino acids linked by a peptide bond
How do you know it is unsaturated? Know how to identify a unsaturated lipid.
the carbon chain has a bend which shows a double bond between
The flow of genetic information is from DNA -> RNA -> protein. Use this figure to explain the process. Label the nucleus, DNA, mRNA, ribosome, and amino acids.
the mRNA interacts with the cell's protein-synthesizing machinery to direct the ordering of amino acids in a polypeptide (occurs in ribosome, located in the cytoplasm). mRNA moves information and directions from the nucleus to cytoplasm where the ribosomes are. The ribosomes then creates proteins with the amino acids with the information and directions brought by the the mRNA.
Type of Protein: Motor and Contractile Proteins -what is the function? -give an example
- Movement -actin and myosin
-What 2 monosaccharides form maltose? -Where is maltose found?
-2 glucose molecules -malt sugar
Notice that there are five nitrogen bases. Which four are found in DNA?
Adenine, guanine, cytosine, thymine
Here is the abbreviated ring structure of glucose. Where are all the carbons? -diagram in question 13
Each corner represents a carbon; each carbon in this figure is labeled 1 through 6.
Define peptide bond
covalent bond in which 2 amino acids are joined by a dehydration reaction
Study your sketch from question 34. Why are the tails from the phospholipid bilayer all located in the interior?
they are in contact with each other and remote from water because they are hydrophobic
Type of Protein: Receptor Protein -what is the function? -give an example
-Response of cell to chemical stimuli -G protein-coupled receptors; tyrosine kinase receptors
Here is a figure that shows the structure of a phospholipid. Label the sketch to show the phosphate group, the glycerol, and the fatty acid chains. Also indicate the region that is hydrophobic and the region that is hydrophilic. -Look for diagram from question 31
- answers are on diagram from question 31 -tail is hydrophobic -head is hydrophilic
Enzymes are an important type of protein. They will be studied in Chapter 8. For now, use this sketch to review what you know about enzymes. Label the active site, the substrate, and the products. Show what happens to water. -Look at diagram from question 39 -Is this reaction dehydration synthesis or hydrolysis?
- answers found on diagram from question 39 -dehydration synthesis
Type of Protein: Enzyme -what is the function? -give an example
-Accelerate chemical reactions -Maltase, pepsin, sucrase
Circle the three classes that are called macromolecules. Define macromolecule.
-Carbohydrates, Proteins, Nucleic Acids -Macromolecules are extremely large on the molecular scale, sometimes consisting of thousands of atoms.
Monomers are connected in what type of reaction? What occurs in this reaction?
-Monomers are connected in a dehydration reaction or condensation reaction -During a dehydration reaction, two monomer molecules are covalently bonded to each other, with the loss of a water molecule. In this reaction, each monomer contributes part of the water molecule that is released during the reaction. This reaction is repeated as monomers are added to the chain one by one, making a polymer.
Type of Protein: Storage -what is the function? -give an example
-Storage of amino acids -Casein, which is the major source of amino acids for baby mammals; ovalbumin, the protein of egg white
Type of Protein: Transport Protein -what is the function? -give an example
-Transport -Proteins embedded in the plasma membranes; aquaporins; hemoglobin
Level of Protein Structure: Quaternary (IV^0) -explanation -example
-aggregation of 2 or more polypeptide subunits -ex. hemoglobin, collagen
Level of Protein Structure: Primary (I^0) -explanation -example
-amino acids linked with a unique sequence -ex. transthyretin
The monomers of proteins are amino acids. Sketch an amino acid here. Label the alpha or central carbon, amino group, carboxyl group, and R group. -know the actual atom arrangement
-answer found in question 41
What are the building blocks of fats? Label them on this figure. -look at the diagram in question 22
-answers are on diagram from question 22
The components of a nucleic acid are a sugar, a nitrogenous base, and a phosphate group. Label each on the figure below. Also label the end of the strand on the left side of the figure below that has the number 5 sugar 5' and the other end of the chain 3'. -look at diagram from question 53
-answers on diagram from question 53
If a fat is composed of three fatty acids and one glycerol molecule, how many water molecules will be removed to form it? Again, what is this process called?
3 water molecule is removed (one for each fatty acid) to join the glycerol. This process is called dehydration synthesis.
In a DNA double helix, a region along one DNA strand has this sequence of nitrogenous bases: 5'-T A G G C C T-3' -Write the complementary strand. Indicate the 5' and 3' ends of the new strand.
3'-A T C C G G A-5'
Consider the following reaction: C6H12O6 + C6H12O6 C12H22O11 A. The equation is not balanced; it is missing a molecule of water. Write it in on the correct side of the equation. B. Polymers are assembled and broken down in two types of reactions: dehydration synthesis and hydrolysis. Which kind of reaction is this? C. Is C6H12O6 (glucose) a monomer, or a polymer? D. To summarize, when two monomers are joined, a molecule of __________ is always removed.
A. C6H12O6 + C6H12O6 C12H22O11 + H2O B. Dehydration synthesis C. Monomer D. water
The large molecules of all living things fall into just four main classes. Name them.
Carbohydrates, Lipids, Proteins, Nucleic Acids
List four important functions of fats.
Energy storage, long-term food reserve in mammals, adipose tissue cushions vital organs, body insulation.
Why can you not digest cellulose? What organisms can?
Humans cannot digest cellulose because they lack the enzyme that can hydrolyze its beta linkages. Humans do posses enzymes that digest starch by hydrolyzing its alpha linkages; however, these enzymes cannot hydrolyze the beta linkages of cellulose because of the distinctly different shapes of these two molecules. Some microbes can digest cellulose into glucose monomers with cellulose enzymes. Many eukaryotic herbivores (cow to termites) have relationships with microbes therefore they can digest cellulose. Also some fungi
To summarize, what are the three components of a nucleotide?
Phosphate group, sugar, nucleoside
Do you remember when, in Chapter 4, we said, "To change the structure, change the function"? Explain how this principle applies to sickle-cell disease. Why is the structure changed?
The blood cell is denatured because the weak bonds in the protein are broken so the shape of the blood cell is lost
Name the correct carbohydrate for each? Has 1-4 B glucose linkages
starch
Have you noticed that all the sugars end in -ose? This root word means _______.
sugar
Enzymes are globular proteins that exhibit at least tertiary structure. As you study Figure 5.20 in your text, use this figure to identify and explain each interaction that folds this protein fragment. -Look at diagram from question 47
Hydrophobic interaction: amino acids with hydrophobic R groups end up in clusters at the core of the protein, out of contact with water. Van der Waals interaction: transient interactions between R groups Hydrogen Bond: weak bonds between the hydrogen of one R group and the oxygen or nitrogen of another R group Disulfide Bridge: links between the sulfhydryl groups of two cysteine amino acids, sulfur to sulfur Ionic Bond: bonds between an R group that is positively charged and an R group that is negatively charged These interactions tend to fold an amino acid chain into a distinctive three-dimensional form. *LOOK AT DIAGRAM TO FOR EACH STEP*
Large molecules (polymers) are converted to monomers in what type of reaction?
Polymers are disassembled to monomers by hydrolysis, a process that is essentially the reverse of the dehydration reaction.