FINAL EXAM SURVIVAL GUIDE
Laboratory Safety
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Always wear goggles when heating, dealing with sharp objects, and using chemicals.
Never heat a closed test tube (with a lid/stopper/cork)
Never heat an object towards your face
Transport
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Diffusion is the movement of substances from HIGH concentration to LOW concentration
Osmosis is the diffusion of water from a HIGH concentration to a LOW concentration
Active transport goes against the concentration gradient, and moves substances from a LOW
concentration to a HIGH concentration
Active transport requires ATP energy.
HIGH concentration means where there is MORE of something
LOW concentration means where there is LESS of that same thing.
A substance will diffuse until the concentration is EQUAL on both sides of the membrane.
Only small molecules are permeable to the cell membrane (water, CO2, O2, glucose, etc.)
Diffusion through a Membrane- STATE LAB
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Glucose is permeable to the membrane
Starch INDICATOR (iodine) is permeable to the membrane
Starch is NOT permeable to the membrane- it is too big
Starch can be broken down into glucose, a simple sugar, so that it can enter the cell.
Starch indicator will turn BLACK in the presence of starch.
Glucose and starch indicator will diffuse in/out of the artificial cell until there is an equal amount inside
AND outside of the bag (homeostasis).
Organelles
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Chloroplast- only in plants, where photosynthesis takes place
Mitochondria- where cell respiration takes place, provides ATP energy for the cell
Vacuole- found in plants, storage of FOOD (starch) and WATER
Cell membrane- controls what enters and leaves cell, “WASTE REMOVAL”
Ribosome- makes proteins
Nucleus- storage of genetic info/DNA, controls cell activities
Cell wall- found in plants only, rigid layer of protection
Cytoplasm- liquid that fills cell- “TRANSPORT”
Enzymes
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Enzymes are proteins catalysts.
Enzymes speed up the rate of chemical reactions in living things
Enzymes have a specific shape that fits only 1 specific type of substrate/reactant
Enzymes only work in specific pH and temperature ranges
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Enzymes will lose their specific shape and no longer catalyze reactions if they go too far out of their pH
and temperature ranges.
The optimum pH and temperature of an enzyme will be found at the highest point on the graph.
Enzymes are similar to antibodies and hormones because they all have specific shapes.
Photosynthesis
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Photosynthesis is a chemical reaction that converts sun energy (light energy) into the organic molecule
glucose (chemical energy)
Photosynthesis uses carbon dioxide and water to make glucose and oxygen
Photosynthesis occurs in the chloroplast.
Cellular Respiration
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Cellular respiration is a chemical reaction that converts chemical energy (food/organic molecules) into
ATP energy (the energy to run all cellular activities)
Cellular respiration occurs in the mitochondria of both plants and animals (all living things needs ATP)
Cellular respiration requires oxygen
Cellular respiration uses oxygen and an organic molecule to make ATP. Carbon dioxide and water are
released as waste products
ATP is the energy used by cells to power all activities, including transport, synthesis, and waste
removal.
Cellular respiration is able to happen because of enzymes.
Organic Molecules
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Organic molecules contain BOTH carbon AND hydrogen
Organic molecules store energy in the chemical bonds between their atoms
Autotrophs MAKE their own organic molecules (glucose, a simple sugar), and Heterotrophs get their
organic molecules by eating other organisms)
Designing an Experiment
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A hypothesis is an IF … THEN… statement that gives a possible answer for the question being asked.
The experimental group receives the experimental variable that you are testing
The control group WILL NOT receive the experimental variable that you are testing
All other conditions must be kept the same between control and experimental group
The data to be collected in any experimental must be measureable (quaNtitative)
EXAMPLE:
o Design an experiment to see the effectiveness of cough medicine:
 Hypothesis- IF I give patients cough medicine, THEN they will cough less
 Experimental Group- People given cough medicine
 Control Group- People not given cough medicine
 Data to be collected- Number of coughs per hour
Making Connections- State Lab
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Heart rate increases during exercise. This is a response by the circulatory system.
Breathing rate increases during exercise. This is a response by the respiratory system.
The response of the heart/breathing rate to exercise is an example of a feedback mechanism.
Respiratory System
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The respiratory system brings oxygen into the body, which is a REACTANT in cellular respiration
The respiratory system removes carbon dioxide from the body, which is a WASTE PRODUCT in cellular
respiration.
Cells need more ATP during exercise. To maintain homeostasis, breathing rate increases to get more
oxygen to the cells faster so that they can do more cell respiration and make more ATP.
Oxygen diffuses into the bloodstream from the alveoli by gas exchange.
Carbon dioxide diffuses out of the bloodstream from the capillary by gas exchange.
Circulatory System
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The body’s transportation system to bring the cells what they need.
Blood carries oxygen from the lungs to the cells
Blood carries carbon dioxide from the cells to the lungs
Blood carries organic nutrients from the small intestines to the cells.
Cells need more ATP during exercise. To maintain homeostasis, heart rate increases to pump blood
deliveries to the cells faster so that they can do more cell respiration and make more ATP. (feedback
mechanism)
Digestive System
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The digestive system breaks down large organic macromolecules such as proteins, lipids, an
carbohydrates into simple organic nutrients that can be used for cellular respiration
Proteins are broken down into amino acids
Lipids are broken down into fatty acids
Carbohydrates are broken down into simple sugars (monosaccharides)
The simple organic nutrients are absorbed into the blood stream so that all cells can do cellular
respiration.
INSULIN is a hormone released by the PANCREAS. Insulin controls blood sugar. If blood sugar is high,
insulin is released. If blood sugar drops, insulin is stopped. This is a FEEDBACK MECHANISM.
Endocrine System
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The endocrine and nervous system are systems that send chemical messages.
The endocrine system is made of glands that release hormones, and the nervous system sends nerve
messages.
Chemical messages are only received by target cells that have a MATCHING RECEPTOR MOLECULE.
If a cell does not have a receptor molecule, it will not receive the message!!
Immune System
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The immune system is the body’s defense system against foreign pathogens such as viruses, bacteria,
yeast, fungi, and other parasites.
Foreign microbes disrupt homeostasis, and cause disease, illness, or death.
There are special white blood cells (B cells, T cells, and engulfing cells) that flag pathogens, engulf
pathogens, and destroy infected cells.
An antiBodY is a special protein flag with a SPECIFIC shape that fits a SPECIFIC antiGEN on a pathoGEN.
The antiBodY is shaped like the letter Y, and signals a pathogen to be destroyed.
An antigen is ANY molecule than can trigger the immune system to respond!!!
A vaccine uses weakened versions on microbes (or parts of them) to build immunity and prevent an
individual from being harmed by a pathogen.
An allergy is when the body recognizes an antigen on a usually harmless environmental substance
and launches an immune response, usually swelling.
HIV is a virus that weakens the immune system by attack T cells.
When the immune system becomes too weak, the HIV virus has turned into the AIDS disease. The
individual is unable to defend attacks by other pathogens such as the flu, or the common cold.
Levels of Organization
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SMALLEST- organelle, cell, tissue, organ, organ system, organism –LARGEST
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The pH scale goes from 0-14 and measures whether a substance is an acid or a base.
0-6 are acids. pH 0 is the strongest acid. pH 6 is the weakest acid.
8-14 are bases. pH 8 is the weakest base. pH 14 is the strongest base.
pH 7 is neutral (pure water)
pH
Enzyme Graphs
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Graph that shows the activity of enzymes.
The highest point of the graph is where the enzyme is working the fastest (catalyzing most reactions).
Enzymes only work in specific pH and temperature ranges. If they go too far out of their temperature
range, they will lose their specific shape (denature) and no longer work.