bio 101 study guide : module 3

Students should be familiar with the following vocabulary terms and understand how to use them appropriately when applying course content:

• Organic = molecules MUST contain BOTH carbon and hydrogen, compound is irreversibly altered

• Inorganic = does NOT contain carbon and hydrogen together, compound will always return to its native state

• Carbon = atomic number is 6, has 4 electrons in its valence shell, carbon tends to share electrons rather than donate or receive them

• Functional Group = combination of atoms attached to the carbon backbone which always reacts in the same way

• Hydroxyl Group = (-OH) polar, attracts water easily

  

• Amino Group = (-NH2) form amino acids

  

• Carboxyl Group = (-COOH) donates H+ which decreases the pH in the solution

  

• Phosphate Group = (-PO4) forms phosphoric acid, important in energy transfer and in DNA

  

• Isomer = two molecules with the same chemical formula but different structures

• Monomer = small molecule that is strung together to make a larger molecule

• Dimer = two monomers joined together

• Polymer = large molecule made of many monomers joined together

• Macromolecule = gigantic and complex molecules

• Dehydration Synthesis = all polymers are assembled the same way, removes a molecular of water (H2O) → links the two subunits together, requires energy

  

• Hydrolysis = breaks down polymers in which reverse of making them, instead of removing a water molecule → you add one, releases energy

  

• Carbohydrate = C H O (1:2:1)

• Lipids (Fats) = C H O but fewer O and more H

• Nucleic Acid = C H O N P

• Protein = C H O N R

• Enzyme = catalysts for reactions

1. Be able to differentiate organic and inorganic molecules. 

   1. If a molecule is organic it will have Hydrogen and Carbon. 

   2. What is native state? The naturally folded and functional three-dimensional structure of a protein or nucleic acid

   3. Which can return to its native state: inorganic

   4. If a molecule has the chemical formula CH4 is it organic or inorganic? Organic

   5. If a molecule has the chemical formula NH3 is it organic or inorganic?

      Inorganic

2. Describe why carbon molecules are versatile as molecular ingredients. 

   1. What is the atomic number of carbon? 6

   2. How many electrons are in the outer shell of carbon? 4

   3. What kind of bonds will carbon form: covalent

   4. When you see one stick connecting two chemical elements like this C-C what does that mean? How many electrons are being shared?

      • represents a single covalent bond

      • they are one pair of electrons (2 electrons)

   5. When you see two sticks connecting two chemical elements like this C=C what does that mean? How many electrons are being shared?

      • represents double bonds

      • they are two pairs of electrons (4 electrons)

   6. If a molecule is made of just carbon and hydrogen, what is it called? 

      hydrocarbon

3. Explain the importance of functional groups.  Be able to identify the following functional groups: hydroxyl, carboxyl, amino, phosphate

   1. A combination of atoms attached to the carbon backbone which always reacts in the same way is called a: functional group

   2. Which functional group is OH? hydroxyl group

      1. What property does OH confer to the molecule? confer alcohol properties to hydrocarbon chain; polar; attract water easily

   3. Which functional group is COOH? carboxyl group

      1. What property does COOH confer to the molecule? confer acid properties to hydrocarbon; donates H+ which decreases the pH in the solution

      2. What makes COOH an acid? it donates H+ which decreases the pH

   4. Which functional group is NH2? amino group

      1. What property does NH2 confer to the molecule? confer anime properties to hydrocarbons to form amino acids

   5. Which functional group is PO4? phosphate group

      1. What property does PO4 confer to the molecule? forms when phosphoric acid dissociates; important in energy transfer and in dna

   6. Which two functional groups are found on an amino acid? amino group & carboxyl group

4. What is an isomer? two molecules with the same chemical formula but different structures

5. Describe how you would determine if two molecules are isomers? check if they have the same chemical formula and compare their structural connectivity

6. Explain the relationship between the following: macromolecule, monomer, dimer, polymer

   1. How many monomers in a dimer? 2

7. Describe why dehydration synthesis and hydrolysis are important reactions to know in biology.

   1. Which reaction builds polymers? dehydration

   2. Which reaction breaks down polymers? hydrolysis

   3. What is removed during dehydration synthesis? water (H2O)

   4. What is added during hydrolysis? water H2O

   5. Which reaction releases energy? hydrolysis

   6. Which reaction requires the addition of energy? dehydration

   7. Why role do enzymes play in hydrolysis or dehydration synthesis reactions? catalysts

8. Describe the general structure & characteristics of the following organic molecules: carbohydrates, lipids, proteins, nucleic acids:

Organic Molecule	Structure	Characteristics
Carbohydrates		C H O 1:2:1
Lipids		C H O fewer O, more H
Proteins		C H O N R
Nucleic Acids		C H O N P

1. General organic molecule info

   1. Which organic molecule has CHO in a ratio 1:2:1? carbohydrates

   2. Which organic molecule has CHO but many more C than O? carbohydrates

   3. Which organic molecule will contain CHON? proteins

   4. Which organic molecule will contain CHONP? nucleic acid

   5. A molecule has the formula C₁₀H₂₀O₂, what is it? lipids

   6. A molecule has the formula C₆H₁₂O₆, what is it? monosaccharide (glucose, fructose, or galactose)

2. Carbohydrates: 

   1. Fill in the following table for the five monomers (monosaccharides) of carbohydrates

1. If Glucose, Fructose, and Galactose all have the same chemical formula, but different structural formulas what would they be considered? isomers

2. What is the chemical formula of Ribose? C5H10O5

3. Where is ribose found? RNA, ATP, and other nucleotides

4. What is the chemical formula for Deoxyribose? C5H10O4

5. Where is deoxyribose found? DNA

2. Describe which two monomers join to make sucrose, lactose and maltose. 

   1. Sucrose is made of: glucose and fructose

   2. Lactose is made of: glucose and galactose

   3. Maltose is made of: glucose and glucose

3. What process is used to join two monosaccharides to make a disaccharide? dehydration synthesis

4. Describe the functions of starch, glycogen, cellulose, chitin, and peptidoglycan. 

   1. Starch is the energy storage molecule of: plants

   2. Glycogen is the short term energy storage molecule of: animals 

   3. Cellulose is a structural molecule in: plant cell walls 

   4. Chitin is a structural molecule in: fungal cell walls and exoskeletons of  

   5. Peptidoglycan is a structural molecule found in: bacterial cell walls

3. Lipids

   1. What are the six functions of lipids? energy storage, cell membrane structure, hormone signaling, insulation, vitamin absorption, and protection of organs

   2. What are the four categories of lipids? fatty acids, glycerides (triglycerides), phospholipids, and sterol lipids (steroids)

   3. What is the long-term energy storage molecule in animals? saturated fat

   4. Are lipids considered hydrophobic or hydrophilic molecules? hydrophobic

   5. What are the building blocks (subunits) of a triglyceride? glycerol and 3 fatty acid

   6. What makes a fatty acid saturated vs unsaturated? saturated if all the bonds between carbon atoms in its chain are single bond; if it has a double bond then the fatty acid is unsaturated because it now has fewer hydrogens

   7. Are saturated fats solid or liquid at room temperature? solid

   8. Identify which of the pictures below represents a saturated fatty acid and which one represents an unsaturated fatty acid. Explain why 

top row is a saturated fatty acid because it has one single bond throughout the whole molecules which makes it look straight while the bottom row has as a double bond which bends the molecules and makes it unsaturated

9. How does a phospholipid differ from a triglyceride? the number of fatty acids they contain and their polarity; phospholipids are not fats, since they have glycerol, two fatty acids, and phosphorus

10. Which part of a phospholipid is hydrophilic? head

11. Which part of a phospholipid is hydrophobic? tail

12. What is the correct organization of phospholipids in a plasma membrane?

    

    C

13. What is the precursor for all steroids?
    pregnenolone
    
    

14. Proteins

    1. List some functions of proteins: structural support, biochemical catalysts, hormones, enzymes, building blocks, and initiators of cellular death

    2. Name the monomers of proteins (what are they made of) and name the bonds they form with each other. amino group (-NH2), carboxyl group (-COOH), and side chain (R group); they form a bond called polypeptide

    3. Describe the basic structure of an amino acid: C H O N R

       1. Name the two functional groups found in amino acids: amino group and carboxyl group

    4. Describe the 4 structural levels of protein organization/structure. 

       1. Which level has a straight chain of AA? primary structure

       2. Which level do alpha helix and beta sheet form? secondary structure

       3. Which level does the 3D structure emerge? tertiary structure

       4. Which level do several polypeptides come together to make a protein? quaternary structure

    5. Explain the system which ensures that proteins fold correctly. 

       1. What is the name of the protein that monitors folding? chaperones

       2. What are misfolded proteins called? prions

    6. Identify why protein structure is so important

       1. Use sickle cell anemia example. individuals with sickle cell disease have a mutation in their DNA code

       2. How many amino acids are “wrong” in sickle cell anemia? as DNA gives the recipe for the protein, the mutation results in insertion of the wrong amino acid

       3. How is the hemoglobin protein affected by this tiny change? in the the red blood cells, the protein did not fold correctly

    7. Describe how a protein could become denatured

       1. List 2 ways to denature a protein. 

          • change in temperature

          • pH level

       2. Does a denatured protein work correctly?

          no

          
          

15. Nucleic acids

    1. The monomers of nucleic acids are called: nucleotides

       1. What are the 3 parts of a nucleotide?

          • sugar (ribose or deoxyribose)

          • phosphate group

          • nitrogenous base (A, T, C, G, or U)

    2. Describe the structure, function and characteristics of DNA and RNA. 

       1. G always pairs: C

       2. A pairs to T in DNA and U in RNA. 

       3. How many hydrogen bonds between A and T? 2 hydrogen bond

       4. How many hydrogen bonds between G and C? 3 hydrogen bond

       5. Which bases are purines? A and G

       6. Which bases are pyrimidines? C,T, and U

       7. What term did Watson and Crick use to describe DNA structure? double helix

    3. Compare and contrast DNA vs. RNA by filling in the table below

4. Name three similarities/commonalities between DNA and RNA

   • both are nucleic acids

   • both contain A, C, and G

   • plays a role in genetic information storage

5. What is the function of ATP? the primary energy of the cell