Biology Mid-Term Study Guide Chapter 1

1. List the steps of the scientific method? Observations Write hypothesis Predict Experiment Make conclusions

2. In science, a hypothesis can only be used if it can be tested.3. Explain Redi’s experiment & be able to list the steps and explain the

purpose. Redi placed raw meat in jars. One jar had no covering, & one jar was

covered with gauze. He wanted to disprove spontaneous generation. People used to think maggots came from meat, not from flies. Redi proved that maggots came from eggs laid by flies, not from the meat itself. The sealed jar had no maggots & the gauze covered jar kept the flies away from the meat.

4. A controlled experiment allows the scientist to isolate and test one variable.

5. When can a hypothesis become a theory? When it is well-tested and supported by much evidence.

6. TRUE → A theory can be revised or replaced.7. List & describe the characteristics of living things and give examples.

Living things are made of cells. Living things reproduce. Living things are based on a universal genetic code Living things grow & develop. Living things obtain and use materials & energy. Living things respond to their environment. Living things maintain stable in internal environment. Living things change over time.

8. In Order from simple to complex: Population: Group of organisms of one type that live in the same

area Community: Populations that live together in a defined area. Ecosystem: Community & its nonliving surroundings Biosphere: The part of Earth that contains all ecosystems.

9. How many centimeters are in 2.4 km? 2400 centimeters

10. TRUE → a compound light microscope can magnify objects up to 1000 times.

11. What is the best reason to use a scanning electron microscope? To produce realistic, & often dramatic, three-dimensional images of

the surfaces of objects.

Chapter 2

1. Draw the atom and label the protons, neutrons, & electrons. Explain the location of each of the subatomic particles? Electrons (-) are in constant motion in the space

surrounding the nucleus Strong forces bind protons (+) & neutrons together to form the

nucleus, which is at the center of the atom.2. What is a water molecule composed of? Draw a water molecule

showing partial charges. What kind of bond occurs between the atoms in a water molecule? Water molecule is composed of two hydrogen atoms & 1 oxygen

atom. Water molecule is a covalent bond

3. Why is water polar? What about the structure makes it polar? Water is polar because there is an uneven distribution of electrons

between the oxygen & hydrogen atoms. 4. What is the reason that ice floats on water? What happens to the

arrangement of the water molecules when water freezes? Ice floats because it is less dense than liquid water and expands

when it freezes. If ice sank to the bottom the situation would be disastrous for fish and plant life in regions with cold winters. When water freezes its molecules come close together and just vibrate in its place.

5. What is the most abundant compound in most living things? Water

6. Know the pH scale. If a substance has a pH of 5 it is an acid.7. Carbohydrates are composed of monomers called monosaccharides.8. How do enzymes affect the speed of a reaction?

By lowering the activation energy which has a dramatic effect on how quickly the reaction is completed.

9. Isotopes are an atom of an element that has a number of neutrons different from that of other atoms of the same element.

10. Covalent bonds are bonds formed by the sharing of electrons between atoms.

11. Acids have the highest H + concentration & the Bases have the highest OH - concentration.

12. Describe & give examples of some of the functions of proteins. Some control the rate of reactions & regulate cell processes Some are used to form bones & muscles Others transport substances into or out of cells or help fight disease

13. Activation energy is the energy needed to get a reaction started

14. Catalyst is a

substance that speeds up the rate of a chemical reaction15. A compound is a substance formed by the chemical combination

of two or more elements in definite proportions. 16. A solution is a mixture of two or more substances in which the

molecules of the substances are evenly distributed A solute is a substance that is dissolved in a solvent to make a

solution A solvent is a substance in which a solute is dissolved to form a

solution

17.

18. Building blocks of... Carbohydrates: Carbon, oxygen hydrogen & oxygen atoms Lipids : carbon & hydrogen atoms Proteins: carbon, hydrogen & oxygen

19. CO2 + H2O → H2COReactants→ Products

20. A chemical reaction is the process that changes one set of chemicals into another set of chemicals.

21. False → Enzymes only work inside & outside the cell. 22. Describe the lock & key hypothesis. Compare enzyme activity to

the lock & key. Lock and key is an analogy of enzyme activity in a cellular

reaction. The lock and key are compared directly to the substrate

and enzyme, because of the high specificity of their physical shape. Enzymes participate in the reaction they catalyze. The reactant molecule (substrate)

binds to the enzyme molecule at a particular location called the active site. (this is compared to the lock with keyhole) The highly specific nature of an enzyme is due to very precisely defined arrangement of atoms in the active site. The substrate molecule must have a matching shape that will fit into the active site. The bond breaking and bond forming processes that transform the substrate into products occur while the substrate is bound to the active site of enzyme. In other words it’s something like a jigsaw puzzle where the substrate fits into the enzyme. The reaction occurs and the substrate then leaves the enzyme as products.

23. Adhesion is the attraction between molecules of different substances; in plants, attraction between unlike molecules.Cohesion is the attraction between molecules of the same substance.Capillary Action is the tendency of water to rise in a thin tube

24. Mass # is the sum of the number of neutrons and protons in an atomic nucleus.Atomic # is the number of protons in an atomic nucleusAtoms have equal numbers of electrons & protons. To find out the number of neutrons Mass Number = (Number of Protons) + (Number of Neutrons)

25. The number of protons is always equal to the number of electrons.

26. Be able to read a graph showing enzyme activity on the y-axis & the temperature on the x-axis.

27. A Hydrogen bond a chemical bond in which a hydrogen atom of one molecule is attracted to an electronegative atom, especially a nitrogen, oxygen, or fluorine atom, usually of another molecule.

Chapter 71. Which organelle contains genetic material & is the control center of the

cell?-Nucleus

2. What is the difference between prokaryotes & eukaryotes? What structures are found in prokaryotes but not in eukaryotes & vice versa?

Prokaryotes are generally smaller and simpler than eukaryotic cells. Prokaryotic cells have genetic material that is not contained in the nucleus. Some prokaryotes contain internal membranes, but prokaryotes are generally less complicated than

eukaryotic cells. Prokaryotic cells carry out every associated with living things. They grow, reproduce, respond to the environment & some can even move by gliding along surfaces or swimming through liquids. Example: bacteria

Eukaryotes are generally larger and more complex than prokaryotic cells. They generally contain dozens of structures and internal membrane & many are highly specialized. Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell. Eukaryotes display great variety. Some eukaryotes live as single-celled organisms. Others form large, multicellular organisms. Plants, animals, fungi, & protists are eukaryotes.

3. FALSE → Cytoplasm is found in outside the nucleus4. Which structures carry out cell movement?

-Microtubules & microfilaments5. Which organelle breaks down compounds into small particle that the

cell can?-Lysosomes

6. Which organelle makes proteins?-Ribosome

7. Which organelle converts chemical energy stored in food (powerhouse)?

-Mitochondria8. What is a major function of the cell membrane?

-It regulates what enters & leaves the cell and also provides protection and support

9. An animal cell that is surrounded by fresh water will burst because the osmotic pressure causes water to move from the outside to the inside.

10. What is an organ system?-A group of organs that work together that work together to

perform a specific function11. Who was the first person to identify & see cells?

-Robert Hooke12. What is a cell membrane?

-A thin, flexible barrier around a cell; regulates what enters & leaves the cell

13. What is the function of the cell wall?-Cell wall is a strong supporting layer around the cell membrane

in plants, algae, & some bacteria14. What is diffusion?

-Process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated

15. Osmosis is the diffusion of water across a selectively permeable membrane

16. What is cell specialization?-the process in which cells develop in different ways to perform

different tasks17. 3-D images can be seen with a scanning electron microscope.18. Which organelles would you find in plant cells but not in animal

cells?-Chloroplast & cell wall

19. What is a tissue?-A group of similar cell that perform a particular function

20. What is the function of the cytoskeleton?-It helps maintain the cell’s shape, as well as movement.

21. Which organisms have cell walls?-Plants, algae & some bacteria

22. What is the structure of the cell membrane?23. Compare & contrast facilitated diffusion, active

transport & passive transport. Facilitated diffusion is the movement

Of specific molecules across the cell Membrane through protein channels.

Active transport is energy requiring process that Moves material across a cell membrane against a concentration difference.

Passive transport is when no energy is required for materials to move across a cell membrane.

24. Be able to explain what would happen if a blood cell was place in a hypertonic solution?

The cell would shrink/shrivel up.25. Be able to explain the 3 parts of the cell theory & explain its

significance to biology. All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells The cell theory is significant to biology because it is useful to

understand that all organisms are made up of cell & complexity of cell in eukaryotes

26. Be able to discuss the levels of organization in multicellular organisms, and explain why these levels are not used to describe unicellular organisms.

Cells Tissues Organs Organ systems These levels aren’t used in unicellular organisms because that

single cell can perform all of the organism’s functions.

27. Be able to interpret a diagram showing diffusion across a selectively permeable membrane. Be able to explain which way the molecules will travel and what will happen.

A B CThere is a high Solute particles move from When equilibrium is reached,Concentration of solute the side of the membrane solute particles continue to On one side of the with a higher concentration diffuse across the membrane Membrane as compared of solute to the side of the in both directions.To the other side of the membrane with a lower Membrane. Concentration of solute. The Solute particles will continue To diffuse across the Membrane until equilibrium Is reached.

Chapter 81. What is the difference between heterotrophs & autotrophs?

Autotrophs make their own food Heterotrophs obtain energy from the foods they consume

2. Draw and ATP molecule? What is an ATP composed of? 5-carbon sugar (ribose), adenine & 3 phosphate groups

3. How do you release & store energy in ATP? The energy in ATP is released by the breaking the chemical bond

between the 2nd and 3rd phosphates. The energy in ATP is stored in the bonds between the phosphate

groups4. What is the difference between ATP & ADP?

ATP has 3 phosphate groups & ADP only has two.5. Describe the findings of...

Jan Van Helmont concluded that trees gain most of their mass from water

Joseph Priestly finds that plants release oxygen.

Jan Ingenshouz finds that aquatic plants produce oxygen bubbles in the light but not in the dark. He concludes that plants need sunlight to produce oxygen.

6. What is the equation for photosynthesis? 6CO2 + 6H12O → C6H12O6 + 6O2

7. What goes into photosynthesis and what goes out? Photosynthesis uses the energy of sunlight to convert water &

CO2 into high energy sugars & oxygen8. 6 molecules of CO2 results in 6 molecules of oxygen9. Pigments are light absorbing molecules10. Why are plants green? What kind of light is absorbed by plants?

What kind of light is reflected by plants? Plants are green because they have a substance called

chlorophyll in them. Plants absorb all colors except green which is reflected.

11. The stroma is the region outside the thylakoid membranes in the chloroplasts.

12. Draw a chloroplast & label the stroma, thylakoid & granum.13. Where in the chloroplasts is the chlorophyll found?

The thylakoid contain the chlorophyll. Chlorophyll molecules are embedded in the thylakoid membranes.

14. Where do the light dependent reactions take place? The light-dependent reactions take place within the thylakoid

membranes of the chloroplasts.15. What are the products of the light-dependent reactions?

Oxygen, ATP & NADPH16. Write the steps of the light-dependent reactions in order.

a) Light absorbed by photosystem II is used to break up water molecules into energized electrons, hydrogen ions & oxygen

b) High-energy electrons from photosystem II move through the electron transport chain to photosystem I

c) Electrons released by photosystem II are energized again in photosystem I. Enzymes in the membrane use the electrons to form NADPH. NADPH is used to make the sugars in the Calvin Cycle

d) The inside of the thylakoid membrane fills up with positively charged hydrogen ions. This action makes the outside of the thylakoid membrane negatively charged 7 the inside positively charged

e) As hydrogen ions pass through ATP synthase, their energy is used to convert ADP into ATP.

17. FALSE → The following are located in the thylakoid mitochondria, electron chain, ATP synthase, photosystem I.

18. Where does the Calvin Cycle take place? In the stroma of the chloroplast

19. What are the products of the Calvin Cycle?

High energy sugars20. Write the steps of the Calvin Cycle.

a) 6 carbon dioxide molecules are combined with 6 5-carbon molecules to produce twelve 3-carbon molecules

b) Energy from ATP and high-energy electrons from NADPH are used to convert the twelve 3-carbon molecules into higher-energy forms.

c) Two 3-carbon molecules are removed from the cycle to produce sugars, lipids, amino acids, & other compounds

d) The 10 remaining 3-carbon molecules are converted back into six 5-carbon molecules, which are used in the next cycle

21.

22. TRUE → Water, temperature & light intensity affect the rate of photosynthesis.

23. What happens if you increase the light intensity that a plant receives?

It increases the rate of photosynthesis.24. What would you expect to happen to plants at a temperature

greater than 45° Celsius? Enzymes can get damaged which slows down the rate of

photosynthesis.