1. W EEK 2 HSA R EVIEW S ESSION Enzymes & Cells

2. E NZYMES Functions: 1. Speed up chemical reactions 2. Lower activation energy Characteristics: 1. Can build up or break down molecules 2. Can be reused 3. Protein (Amino Acid) Environmental Impact: 1. Temperature 2. pH 3. Concentration

3. P ARTS OF AN E NZYME R EACTION

4. Q UESTION 1 1. Amylase is an enzyme that allows the human body to digest starch. Which of these diagrams best represents part of the structure of amylase?

5. Q UESTION 2 Which of these correctly matches the molecule with its function? A. lipid—stores genetic information B. vitamin—supplies energy to cells C. enzyme—speeds up chemical reactions D. carbohydrate—manufactures cell membranes

6. Q UESTIONS 3 & 4 Use the information and the diagram below to answer the following items. Catalase is an enzyme found in the tissues of plants and animals, including humans. Catalase helps prevent a toxic buildup of hydrogen peroxide in cells by breaking it down into water and oxygen gas. Several students conduct an experiment to test the effects of pH on the activity of catalase. Each test tube contains a solution of hydrogen peroxide and water at various pH levels. The liver tissue is a source of catalase. The diagram below represents the results of their experiment. 3. Which of the following are the building blocks of catalase? A. monosaccharides B. nucleic acids C. vitamins D. amino acids 4. Based on the students’ results, catalase works best at a pH of A. 1 B. 4 C. 7 D. 10

7. Q UESTION 5 Use the information and the graph below to answer the following question. Catalase is an enzyme found in plant and animal cells. Hydrogen peroxide is a harmful substance found in cells. Catalase causes hydrogen peroxide to break down into water and oxygen. A student conducted an experiment to determine whether plant and animal cells have the same amount of catalase. She used liver and potato tissues in the experiment. The student followed the procedures below. Label two identical test tubes, 1 and 2. Pour 10 milliliters of hydrogen peroxide solution (1% concentration) into each test tube. Add a small piece of liver tissue to Test Tube 1. Add a small piece of potato tissue to Test Tube 2. Collect the oxygen released from each test tube for 25 seconds. Measure and record the volume of oxygen for each test tube. The graph below shows the results from the experiment. The student conducted a second experiment. She boiled the liver tissue completely and added it to the hydrogen peroxide solution. She observed that little to no oxygen was released in the second experiment. 5. Which of these statements best supports the student’s observations? A. Exposing catalase to high temperatures makes it inactive. B. Exposing catalase to high temperatures changes it into a different enzyme. C. Boiling liver breaks down hydrogen peroxide faster. D. Boiling removes oxygen from the liver.

8. Q UESTION 6 Use the information and the graph below to answer the following question. Scientists wanted to study the effect of water temperature on the swimming speed of goldfish. They set up an experiment in which they raised populations of goldfish in two different aquariums. Population 1 was raised at 5°C. Population 2 was raised at 25°C. All other variables were constant in both aquariums. The results of this experiment are shown in the graph below. 6. Which of these is most affected in the cells of the goldfish when the water temperature is lowered? A. enzyme activity B. pH level C. DNA base sequence D. salt concentration

9. Q UESTION 7 Cells in the stomach produce pepsin, an enzyme, to help digest food. Pepsin works best at a pH of 2. Which of these graphs most likely shows what will happen to the activity of pepsin as the pH of the stomach is increased? A. B. C. D.

10. C ELL P ARTS

11. T YPES OF C ELLS Eukaryote Prokaryote Nucleus Membrane bound organelles CAN be multicellular No Nucleus No membrane bound organelles CAN NOT be multicellular

12. C ELL P ARTS - O RGANELLES OrganelleFunctionPlant or Animal (or both) Cell Membrane Cell Wall Chloroplast Cytoplasm Mitochondrion Nucleus Ribosome Vacuole

13. T YPES OF E UKARYOTIC C ELLS

14. Q UESTIONS 8 & 9 Scientists have recently discovered a new species that lives attached to the side of a tree. An organism from this new species is multicellular has cell walls has vascular tissues makes its own food has structures that absorb moisture from the air 8.Which of these terms best describes this new organism? A.omnivore B.eukaryote C.herbivore D.prokaryote 9. Which of these is NOT true about cells in the new organism? A. They contain nuclei. B. They use vacuoles for storage. C. They contain mitochondria. D. They use pseudopodia to move.

15. Q UESTION 10 Prokaryotic cells possess all of the following EXCEPT A. cell membrane B. ribosomes C. cell wall D. nuclear membrane

16. Q UESTION 11 Cyanide is a poison that prevents mitochondria from using oxygen. As a result, the mitochondria cannot produce A. lipids B. sugar C. minerals D. energy

17. Q UESTION 12 Maryland white oak trees make their own food. Their cells contain structures that capture energy from the sun. What are these structures? A. chloroplasts B. nuclei C. mitochondria D. ribosomes

18. Q UESTION 13 Use the information and the diagrams below to answer the following item. A student observed different types of cells under a microscope. Four of the cells he observed are shown below. 13. Cell 4 has many hair-like structures that it uses for movement. What are these structures called? A. cilia B. flagella C. vacuoles D. pseudopodia

19. Q UESTION 14 Which cell structure contains molecules that direct cell activities? A. nucleus B. ribosome C. mitochondrion D. chloroplast

20. Q UESTION 15 During a trip to the beach, Allen finds a colony of sea anemones on a rock. These sea anemones are green and get their color from tiny single-celled algae that live in their tissues. The algae produce food for the anemones while the anemones provide a place for the algae to live. A drawing of a mobile form of the single-celled green algae is shown below. Which of these structures help this algae move? A. flagella B. cilia C. pseudopodia D. vacuoles

21. ORGAN S YSTEMS Body SystemMain OrgansFunction Circulatory Excretory Respiratory Endocrine

22. L EVELS OF ORGANIZATION Remember that the body always wants to achieve _________. It is difficult to do this when there are so many different activities going on in the body at all times. Communication among organ systems, organs, tissues, and individual cells is vital to reaching ___________. Cell Tissue Organ Organ System Homeostasis

23. Q UESTION 16 Which of these is not a direct function of the skeletal system? A. blood circulation B. muscle attachment C. support of the body D. protection of the organs

24. Q UESTION 17 What is the primary role of the endocrine system? A. to produce chemicals that affect other parts of the body B. to remove waste products from the blood C. to defend the body against illness and infection D. to coordinate movement of the body

25. Q UESTION 18 Which of these body systems transports glucose and other substances in the blood to the cells of the body? A.Digestive system B.Endocrine system C.Circulatory system D.Reproductive system

26. Q UESTION 19 The human body functions properly when organ systems work together. Which organ system works with the muscular system to control muscle contraction? A. circulatory B. excretory C. nervous D. reproductive

27. Q UESTION 20 The kidneys regulate the levels of many chemicals and ions in the body. Which term best describes this process? A. digestion B. circulation C. homeostasis D. meiosis

28. Q UESTION 21 Use the information below to answer the following item. Hummingbirds need large amounts of energy to flap their wings between 60 and 200 times per second. Their wings beat so rapidly that it is difficult to see them move. They often appear suspended in air for extended periods of time without changing their location. Hummingbirds have long bills and grooved tongues to reach into flowers to feed on flower nectar. They also feed on insects. 21. The body system most directly interacting with the skeletal system to enable hummingbirds to beat their wings between 60 and 200 times per second is the A. digestive system B. muscular system C. endocrine system D. circulatory system

29. Q UESTION 22 Which of these is a function of the circulatory system in a mammal? A. the release of energy B. the regulation of temperature C. the movement of organelles D. the transmission of electrical impulses