CHEMISTRY BIOCHEMISTRY BIOLOGY REVIEW ANSWERS

The Study of Life 2. Draw an atomic molecule of water and label the parts. Include the following: covalent bond, hydrogen bond, +ends, -ends, hydrogen, oxygen. Answer: COVALENT BOND

The Study of Life 3. Why is water considered to be a polar molecule? What is the net charge of water? Answer: oxygen atom attracts more electrons In each water molecule, the oxygen atom attracts more than its "fair share" of electrons neutral Zero Net Charge Water is neutral (equal number of e- and p+) --- Zero Net Charge

The Study of Life 4. Describe the hydrogen bonding between water molecules. Answer: Hydrogen Bonds Are Week bonds Between Water Molecules

The Study of Life 5. List the four most important properties of water discussed in class. Answer:CohesionAdhesion High Specific Heat High Heat of Vaporization

The Study of Life 6. Describe cohesion and how it leads to a property of water called surface tension. Answer: Attraction between particles of the same substance (why water is attracted to itself) Attraction between particles of the same substance ( why water is attracted to itself) Results in Surface tension (a measure of the strength of water’s surface) Results in Surface tension (a measure of the strength of water’s surface)

7. Describe adhesion and how it leads to a property of water called capillarity. Answer: Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton. Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton. gives water the ability to “climb” structures

The Study of Life 8. What is a calorie? Why is water considered a substance with a high specific heat? Answer: Amount of heat needed to raise or lower 1g of a substance 1° C. Amount of heat needed to raise or lower 1g of a substance 1° C. Water resists temperature change, both for heating and cooling. Water resists temperature change, both for heating and cooling.

The Study of Life 9. What is heat of vaporation? Why is water considered a substance with a high heat of vaporation? Answer: Amount of energy to convert 1g of a substance from a liquid to a gas In order for water to evaporate, each gram must GAIN 540 calories (temperature doesn’t change o C).

The Study of Life 10. Why don’t lakes freeze in winter and kill all aquatic life? Answer: Ice is less dense Ice is less dense as a solid than as a liquid (ice floats)

The Study of Life 11. Define homeostasis and list four ways water helps to maintain homeostasis in living things. Answer: Ability to maintain a steady state despite changing conditions Water is important to this process because: a. Makes a good insulator b. Resists temperature change c. Universal solvent d. Coolant

The Study of Life 12. What two parts make up a solution? Use the two terms to describe concentration. Answer: Evenly distributed substance in another. Concentration = amount of solute in solvent. SOLUTE Substance that is being dissolved SOLVENT Substance into which the solute dissolves

The Study of Life 13. Describe acids. Where are they found on the pH scale. Answer: More H+ than OH- in a solution. Below pH 7 on a pH scale.

The Study of Life 14. Describe bases. Where are they found on the pH scale. Answer: More OH- than H+ in a solution. Above pH 7 on the pH scale.

The Study of Life 15. What are buffers and why are they important to living things? Answer: Weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH (neutralization). **Produced naturally by the body to maintain homeostasis

The Study of Life 16. Describe what the term organic means. Cells are made up of mostly water. What molecules make up the rest? Which six elements make the majority of living things? Answer: Organic molecules contain carbon and make up living things. Organic molecules make up the part of cells that is not water. CHONPS are the elements that make up living things

The Study of Life 17. Why is carbon considered a versatile element? Answer: Carbon can share its electrons with other atoms to form up to four covalent bonds

The Study of Life 18. What are polymers? What is another name scientists use for polymer? Answer: Polymers are built from smaller molecules called monomers Macromolecules

The Study of Life 19. List the four major categories of macromolecules. Answer: CARBOHYDRATES LIPIDS PROTEINS NUCLEIC ACIDS

The Study of Life 20. Describe dehydration synthesis. Draw an example. Answer: Cells link monomers by a process called condensation or dehydration synthesis (removing a molecule of water)

The Study of Life 21. Describe hydrolysis reaction. Draw an example. Answer: Cells break down macromolecules by a process called hydrolysis (adding a molecule of water)

The Study of Life 22. List 3 monosaccharides. Why are they considered to be isomers? Answer: Include glucose, fructose, & galactose Same chemical formula different structure

The Study of Life 23. How are disaccharides formed? List 3 examples of disaccharides. What is the bond called? Answer: Dehydration synthesis.  Sucrose (table sugar)  Lactose (Milk Sugar)  Maltose (Grain sugar) Glycosidic bond between monosaccharides.

The Study of Life 24. Define polysaccharide and list 3 examples. Answer: Polymers of monosaccharide chains made of monosaccharide monomers Starch, Cellulose, Glycogen

The Study of Life 25. What is the name of the glucose storage molecule in plants? Animals? Answer: 1.Starch 2.Glycogen

The Study of Life 26. What is the structural sugar that makes up the cell walls of plants? Answer: Cellulose

The Study of Life 27. List 4 examples of lipids. Why are lipids considered “hydrophobic”? Answer: Fats, Oils, Steroids, Wax They do not dissolve in water

The Study of Life 28. Give 4 functions of lipids. Answer: Insulate Protect organs Store energy Act as hormones

The Study of Life 29. Briefly describe the difference between saturated and unsaturated fats. Answer: Saturated fats have no double bonds between carbons Unsaturated fats have at least one double bond between carbons

The Study of Life 30. Make a sketch of a triglyceride.

The Study of Life 31. Sketch a phospholipid and label: hydrophilic head, hydrophobic tail, phosphate carboxyl group, fatty acid tail. Answer:

The Study of Life 32. Describe the structure of a steroid. Sketch. Answer: The carbon skeleton of steroids is bent to form 4 fused rings

The Study of Life 33. Describe the structure of a protein. Answer: Proteins are polymers made of monomers called amino acids Proteins are used to build cells, act as hormones & enzymes, and do much of the work in a cell

The Study of Life 34. Give 4 uses of proteins. Answer: Proteins are used to build cells, act as hormones, act as enzymes, and provide transport channels through cell membranes

The Study of Life 35. How many amino acids are there? Draw and describe the structure of an amino acid. Answer: 20 Carboxyl group Amino group R group

The Study of Life 36. Water is formed when two amino acids join. What kind of reaction is the formation of a dipeptide? Answer: Dehydration Synthesis

The Study of Life 37. What macromolecule makes up enzymes? What is their main function? Answer: Proteins. Speed up chemical reactions in living things. Lower activation energy.

The Study of Life 38. Draw the lock and key model of enzyme catalyzed reactions. Answer:

The Study of Life 39. List the four levels of organization of proteins. Answer: Primary, Secondary, Tertiary, Quaternary (d) Quaternary structure (a) Primary structure (b) Secondary structure (c) Tertiary structure

The Study of Life 41. What are the monomers of nucleic acids? Draw a nucleotide monomer. Answer: Nucleotides

The Study of Life 42. List two types of nucleotides. Answer: DNA, RNA Monomers

The Study of Life 43. Describe the structure of RNA. Answer: 5 carbon sugar – Ribose, Nitrogen Base, Phosphate group

The Study of Life 44. Describe the structure of DNA. Answer: 5 Carbon Sugar-deoxyribose, Nitrogen Base, Phosphate group -monomers. Macromolecule is double stranded and joined by hydrogen bonds

The Study of Life 45. Make a quick sketch (Ladder model) of DNA. Answer: Bases include G, C, A, T

The Study of Life 46. STUDY the macromolecule table below. USE THE ONE ON THE STUDYGUIDE Macromolecules, Biomolecules, Organic Compunds Elements *From the Periodic Table of Elements Subunits Monomers, Building Blocks Functions: Why are they important? Examples: Where can we find them? (polymers) Test(s) Carbohydrates C,H,O 1:2:1 ratio Ex: C 6 H 12 O 6 Glucose (simple sugar) monosaccharides (simple sugars) *Short-term energy storage *Quick-release energy *Starch *Glycogen (liver) *Sugars – glucose, fructose, sucrose *Celluose – plant cell walls Iodine: turns purple/blue in the presence of starch Benedict’s Solution: turns copper in the presence of simple sugars such as glucose Lipids: Fats C,H, very little O Carbon, hydrogen, very little oxygen Fatty Acids *Insulation: store body heat *Protection: cell membranes *Long-term energy storage Fats Oils Waxes Steroids Cholesterol Brown Paper Bag Test Nucleic Acids Found in the cell nucleus C,H,O,N,P Carbon, Hydrogen Oxygen, Nitrogen Phosphorus Nucleotides made of: 1) Nitrogen base 2) Sugar compound 3) Phosphate group Store and transmit genetic information DNA Deoxyribonucleicacid Sugar: deoxyribose RNA Ribonucleicacid Sugar: ribose None ProteinsC,H,N,O, P,S Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur Amino Acids *Joined by peptide bonds to form a polypeptide chain (protein) *speed up chemical reactions (enzymes) * bodiy structure *Transport materials in and out of the cell *Enzymes End in “ase” *Hemoglobin Biuret Test: blue solution turns violet in the presence of proteins or any molecule with peptide bonds