Exploring the Micro-universe of the Cell Chapter 1

1. What is biochemistry? Give an example. Biochemistry is the study of the chemistry of reactions in living things including the chemical substances and processes involved. - eg. breathing

- Carbon and hydrogen. 2. Distinguish between polar and nonpolar bonds. 3. What elements make up an organic compound? - Polar bonds have an unequal sharing of electrons whereas nonpolar bonds have an equal sharing of electrons.

4. A macromolecule is a very large molecule composed of smaller subunits linked together, give examples of this. - Polysaccharides, lipids, proteins, and nucleic acids

5. Which organic compounds have the chemical formula C n H 2n O n ? Carbohydrates 6. Name and describe the three main subunits of carbohydrates. - Monosaccharides – simple sugar Disaccharides – double sugar Disaccharides – double sugar Polysaccharides – complex carbohydrate consisting of many simple sugars Polysaccharides – complex carbohydrate consisting of many simple sugars

7. What is the main difference between starch and glycogen? - Starch is used for energy storage in plants whereas glycogen performs the same functions in animals. 8. Cattle, rabbits, and termites obtain nourishment from the cellulose in plant cell walls. Why is the food energy in cellulose not directly accessible to humans? - The human gut does not host the bacterial species needed to break cellulose down into glucose units and release energy.

9. What purpose do lipids serve in animals? - Long-term nutrient and energy storage, insulation, cushioning of internal organs and hormones to send messages around the body 10. Name and explain the differences between two different types of fatty acids. - Saturated fatty acids – only single bonded carbons Unsaturated fatty acids – one or more double bonds between carbons (kinks) Unsaturated fatty acids – one or more double bonds between carbons (kinks)

11a) What is a polypeptide? -a chain of amino acids -a chain of amino acids 11 b) What is the name of the bond between amino acids? -peptide bond joins amino acids. -peptide bond joins amino acids. 12. A protein may unfold or change shape, when this happens it is said to have been denatured. What could cause this? - Extreme temperatures, extreme pH conditions, or harsh chemicals

13. How many amino acids (of twenty) are considered to be essential amino acids? - Eight 14. What are the long chains of linked subunits called in nucleic acids? - Nucleotides 15. Who created the first usable electron microscope? - James Hillier

16. A phospholipid has a ______ head group and a ______ tail group. - Polar or hydrophilic Nonpolar or hydrophobic Nonpolar or hydrophobic 17. What does the fluid – mosaic model represent? What is it mainly made of? - The cell membrane….Phospholipid bilayer + proteins 18. The steady states that results from maintaining near – constant conditions is in the internal environment of a living thing is called what? - Homeostasis

19. Define diffusion. - Diffusion is the movement of molecules from a more concentrated region to a less concentrated region. 20. What is the difference in concentrations between regions called? - Concentration gradient 21. What is the diffusion of a solvent across a semi-permeable membrane called? - osmosis

22. What is a cell with a water concentration that equals the water concentration inside the cell considered to be? - Isotonic 23. What is it called when there is greater water concentration outside the cell than inside the cell? In this condition what may happen to the cell? -Hypotonic, cytolysis- the cell will burst 24. If the water concentration inside the cell is greater than outside the cell, what are the conditions called? In this condition what may happen to the cell? -Hypertonic, plasmolysis

25. What facilitates the movement of glucose molecules from a more concentrated region to a less concentrated region? What type of passive transport is this? - Carrier Protein, Facilitated diffusion 26. What allows charged particles to pass through the lipid bilayer? - Channel protein 27. What type of transport requires energy? - Active transport

28. Name and describe the three different types of endocytosis. - Pinocytosis – intake of a small droplet of extracellular fluid Phagocytosis – Intake of a large droplet of extracellular fluid Phagocytosis – Intake of a large droplet of extracellular fluid Receptor–Assisted endocytosis – intake of specific molecules that attach to special proteins in the cell membrane Receptor–Assisted endocytosis – intake of specific molecules that attach to special proteins in the cell membrane 29. What possesses a uniquely shaped projection or cavity that fits the shape of only one specific molecule? - Membrane receptors

30. What is exocytosis? - (opposite of endocytosis) The vesicle membrane fuses with the cell membrane; the contents of the outwards-bound vesicle are secreted into the extracellular fluid.

THE END!!! Proceed to Chapter 2 Review….