Biochemistry Unit Review Part 1

Biomolecules “Organic” molecules have carbon. “Inorganic” molecules do not have carbon.   Monomers are small parts that make up a large polymers. Monomer + Monomer + Monomer = Polymer

Biomolecules Carbo-hydrate C, H, O Fast energy Organic Molecule Elements Function Monomer Test Carbo-hydrate C, H, O Fast energy Monosaccharides (like glucose) Benedict’s – glucose Iodine - starch Lipid Store long-term energy, make up cell membranes Fatty acids and glycerol Paper bag Protein C, H, O, N Growth and repair, speed up chemical reactions Amino acids Biuret’s Nucleic Acid C, H, O, N, P DNA: carries hereditary info RNA: makes proteins Nucleotides Is it living?

Water & pH Water is a universal solvent – it dissolves most molecules and ions.   pH is a measure of the amount of Hydrogen ions in a solution. pH scale goes from 0 – 14. 1-6 = Acid – the lower the pH, the stronger the acid. Ex. 2 is a stronger acid than 5 7 = NEUTRAL – based on pure water 8-14 = Base (alkaline) – the higher the pH, the stronger the base. Ex. 14 is a stronger base than 11

Enzymes Enzymes are a special type of protein that speeds up a chemical reaction by lowering the activation energy of a reaction.   Enzymes are biological catalysts The material an enzyme works on is called the substrate. The pocket or groove where the substrate fits into on the enzyme is called the active site. Enzymes are named for the substrate that they work with. Names usually end in –ase. Enzymes can be “denatured” by a change in temperature or a change in pH.

Practice Questions

1. A molecule that is found on the surface of most cells is responsible for communication between the cells. This molecule is made up of long chains of amino acids and is specific to each cell type. This molecule is a   lipid carbohydrate DNA strand Protein

2. Which statement best describes the function of a lipid in a cell?   storing and transmitting heredity forming part of biological membranes forming amino acid chains storing phosphorus

3. Which of the following factors is most likely to affect the function of an enzyme?   catalysts size of beaker proteins temperature

4. Which of the following statements best describes a function of an enzyme?   All enzymes work on all substrates. Enzymes are specialized proteins that serve as catalysts. Enzymes are carbohydrate-based molecules in all cells. The structure of enzymes is changed during a chemical reaction.

5. Which of the following substances would show a positive brown paper test for lipids?   apples bacon crackers water

6. Which pH indicates a substance that is more basic than a substance with a pH of 9?   6 2 8 12

7. Which of the following is a list of elements that make up the structure of a carbohydrate?   carbon, nitrogen, oxygen hydrogen, carbon, oxygen nitrogen, sulfur, oxygen oxygen, carbon, phosphorus

8. Which of the following is a function of proteins?   storing energy storing waste growth and repair breaking chemical bonds

9. Which of the following organic molecule tests is correctly paired with its organic molecule?   proteins – brown paper glucose – biuret starch - iodine lipid – benedicts

10. Which biomolecules store and transmit genetic information?   carbohydrates lipids nucleic acids proteins

11. Which of the following best describes the function of carbohydrates?   They code for proteins. They form biological membranes. They provide a source of energy for an organism. They control reaction rates in a cell.

Biochemistry Unit Review Part 2

The Cell Theory The cell theory was developed with the help of the light microscope. The cell theory states that: 1. all organisms are composed of cells 2. cells are the basic unit of structure and function in living things 3. cells come from pre-existing cells

The Cell Theory Cell Theory People: a. Anton von Leeuwenhoek  microorganisms b. Robert Hooke  named cells c. Matthias Schleiden  all plants made of cells d. Theodore Schwann  all animals made of cells e. Rudolph Virchow  new cells come from existing cells.

Microscopes Total Magnification = eyepiece (ocular lens) x objective lens Eyepiece = 10x Objectives = 10x, 40x, 65x Greatest possible magnification = Ex. Total magnification 600x = Eyepiece 10x X Objective 60x Under the microscope, letters get put upside down and backwards. Ex. “e” appears as “___”. Types of microscopes: 1. light microscope 2. scanning electron microscope 3. transmission electron microscope

Prokaryotes vs. Eukaryotes Make a Venn diagram using Nucleus Organelles DNA Cell membrane the following words: Capsule Reproduce Plants Bacteria Animals

Eukaryotic Organelles Nucleus – controls the cell (where DNA is found) Ribosomes – site of protein synthesis (make proteins) Plasma (Cell) Membrane – controls what comes in and out Endoplasmic reticulum– series of channels that act as a transport system Golgi Apparatus – packs, sorts, and ships molecules Mitochondria – powerhouse; makes energy; site of cellular respiration Chloroplast – site of photosynthesis Vacuole – stores water, food and waste Cell wall – used for structure and support in plant cells

Eukaryotic Organelles Plant cells are different from animal cells in three ways: 1. plant cells have a cell wall, animal cells don’t 2. plant cells have chloroplasts, animal cells don’t 3. plant cells have larger vacuole

Practice Questions

1. If an organism does not have membrane-bound organelles, what is it called?   simple eukaryotic prokaryotic complex

2. Which organelle pictured is responsible for transforming energy?   a. b. c. d.

3. During the period from 1838-1855, German scientists Matthias Schleiden, Theodor Schwann, and Rudolph Virchow contributed greatly to the understanding of plant and animal cells. Their cell theory includes all of the following ideas except which one?   All living things are made of cells. Cells are the basic units of structure and function of living things. Cells come from pre-existing cells. Viruses are not made of cells.

4. Prokaryotic and eukaryotic cells are distinguished from each other by which of the following?   Prokaryotic cells include most cells, other than bacteria, and lack a nucleus and membrane-bound organelles. Prokaryotic cells include mainly bacteria, and lack a nucleus as well as membrane-bound organelles. Prokaryotic cells include most cells, other than bacteria, and contain a nucleus and membrane-bound organelles. Prokaryotic cells include mainly bacteria, and contain a nucleus as well as membrane-bound organelles.

5. Which of the cell organelles labeled below helps you determine if this is an animal cell or a plant cell?   nucleus cell wall ribosomes mitochondria

6. What is the function of the Golgi apparatus?   manufacture proteins package and transport proteins store proteins break down proteins to release energy

7. A student identifies an unknown cell as being eukaryotic 7. A student identifies an unknown cell as being eukaryotic. Which of the following did she most likely identify in order to draw this conclusion?   nucleus cell wall chloroplasts cell membrane

8. Which of the following best describes the function of a ribosome?   making proteins digesting lipids, carbohydrates and proteins storing water, proteins, salts and carbohydrates providing structural support for the cell

Biochemistry Unit Exam Review Part 3

Cell Membrane The cell membrane (plasma membrane) is made up of two layers of lipids, so it is called a lipid bilayer.   Proteins can also be found inside the membrane. They can act as receptors, channels and pumps.

Cell Membrane The lipid bilayer contains phospholipid molecules with non-polar tails and polar heads. They hydrophobic tails are “water hating”, while the hydrophilic heads are “water loving”. They are arranged in the membrane with the tails together and the heads on the outside.

Cell Membrane Most biological membranes are “selectively permeable”, or some substances can pass across the membrane while others cannot.

Cell Transport The selective permeability of the cell membrane is most closely associated with the maintenance of homeostasis.   Two main types of transport are passive and active. Passive Transport – does not require energy; moves molecules from high concentration  low concentration. Diffusion – molecules move from high  low Osmosis – water moves from high  low (water moves from less salt to more salt) Facilitated Diffusion– large molecules move from high  low through a transport protein

Cell Transport Active Transport – requires energy (ATP); moves substances from low concentration  high concentration.   Equilibrium – the concentration of dissolved substance is the equal throughout a system.

Cell Transport What happens to a cell when … it is placed in a solution with a higher salt concentration – it will shrink it is placed in a solution with the same salt concentration stay the same it is placed in a solution with lower salt concentration – it will swell

Photosynthesis Photosynthesis is the conversion of light into chemical energy. Equation: CO2 + H2O + Light  C6H12O6 + O2 Carbon dioxide + Water + light energy  Glucose (sugars) + oxygen   Photosynthesis occurs in the chloroplast and the sunlight required for the reaction is absorbed by the chloroplast pigment chlorophyll. There are 2 stages to photosynthesis: 1. Light-dependent (Electron Transport Chain) 2. Calvin Cycle (Light-independent)

Aerobic Cellular Respiration Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.  Equation: C6H12O6 + O2  CO2 + H20 + ATP (energy) Glucose + oxygen  Carbon Dioxide + water + ATP   Cellular respiration occurs in the mitochondria. The most ATP is made during aerobic cellular respiration (36 / molecule of glucose) There are 3 stages to aerobic cellular respiration: Glycolysis Kreb’s Cycle Electron Transport Chain

Anaerobic Cellular Respiration Anaerobic respiration occurs when there is a lack of oxygen for the cells.   Anaerobic respiration has 2 stages: Glycolysis Fermentation There are 2 types of fermentation: Lactic Acid Forms lactic acid as a waste product. Lactic acid creates sore muscles after exercising. Alcoholic Forms ethanol as a waste product. Used in making bread, beer & wine.

Practice Questions #3 and #4

1. A cell moves particles from a region of lesser concentration to a region of greater concentration by   active transport facilitated diffusion osmosis passive transport

2. Which conditions shown below may cause a cell to burst?

3. What cell process is responsible for the transport shown below? active transport osmosis facilitated diffusion passive transport

4. Which process does an organism use to move large molecules into a cell?   simple diffusion exocytosis endocytosis facilitated diffusion

5. Blood plasma and sea water have nearly the same salt concentration 5. Blood plasma and sea water have nearly the same salt concentration. What will happen to a red blood cell placed in pure water?   it will swell it will disintegrate it will shrink it will divide

6. Cells have a selectively permeable membrane 6. Cells have a selectively permeable membrane. What is the primary purpose of this membrane?   to keep all of the cytoplasm inside the cell to control which materials enter and leave the cell to allow photosynthesis to occur to manufacture proteins

7. Which of the following statements about osmosis and diffusion is correct?   Osmosis requires energy and diffusion does not. Both osmosis and diffusion involve the movement of molecules from areas of higher concentration to areas of lower concentration. Diffusion is the movement of water from areas of higher concentration to areas of lower concentration. Osmosis is the movement of water from areas of lower concentration to areas of higher concentration.

8. Which form of transport is represented in the illustration below?   facilitated transport diffusion active transport osmosis

9. An animal cell is placed in a solution of distilled water 9. An animal cell is placed in a solution of distilled water. If left overnight, this cell will   swell and burst shrivel and die undergo chemosynthesis remain the same, since it has a cell wall to protect it

1. Energy is released from ATP when the bond is broken between   two phosphate groups ribose and a phosphate group adenine and a phosphate group adenine and ribose

2. How are the processes of photosynthesis and respiration linked?   One takes place during the day, the other at night. One takes place in animals, the other in plants. The reactants of one are generally the products of the other. They are identical, but in the reverse order of each other.

3. Which of the following produces the greatest amount of ATP?   gylcolysis Krebs cycle Electron transport chain fermentation

4. Which of the following statements about photosynthesis is correct?   The products of photosynthesis are sugar and oxygen. Photosynthesis occurs in mitochondria. Sunlight is not necessary for photosynthesis to occur. The products of photosynthesis are sugar and water.

5. Which of the following is the correct sequence of events in the process of photosynthesis?   Calvin cycle, electron transport chain, absorption of light energy. absorption of light energy, Calvin cycle, electron transport chain electron transport chain, absorption of light energy, Calvin cycle absorption of light energy, electron transport chain, Calvin cycle

6. A cell that is capable of carrying out both photosynthesis and respiration is probably a   prokaryotic cell mitotic cell plant cell animal cell

Light + 6H20 + 6CO2  C6H12O6 + 6O2 + ATP 7. The equation below summarizes what biological processes?   Light + 6H20 + 6CO2  C6H12O6 + 6O2 + ATP chemophotosynthesis fermentation photosynthesis cellular respiration

8. During strenuous exercise, animals cannot take in enough oxygen to supply their cells with the necessary oxygen. As a result, they carry out lactic acid fermentation to supply their cells with the necessary energy. Lactic acid fermentation is a type of   anaerobic respiration aerobic respiration alcoholic respiration ATP respiration