Download Biology – Unit 3 Review

Biology – Unit 3 Review
Vocabulary
Fitness
The ability of an organism to cope or endure its environment.
Amylase
An enzyme found in saliva that breaks down starch (complex sugar) into maltose (a
simple sugar).
Enzyme
A protein that facilitates a chemical reaction.
Glucose
A simple sugar. C6H12O6 is its chemical formula, consisting of 6 carbon atoms, 12
hydrogen atoms and 6 oxygen atoms. Produced by photosynthetic plants and bacteria,
this molecule is the principal energy source for most organism’s metabolism.
Starch
A complex sugar. Starch is a macromolecule that results from plants needing to store
extra glucose in a more compact form.
Substrates
The molecules on which enzymes act.
Glycogen
Another macromolecule that results from the need to store extra glucose. This is the chief
Carbohydrate used by animals for energy storage.
Metabolism
All the chemical activities and changes that take place in a cell or an organism.
Heart Rate
How many times the heart beats per unit of time. Usually recorded in beats per minute.
Diet
The food and liquids an organism consumes.
Protein
An organic compound composed of one or more polypeptide chains of amino acids. Most
Structural materials and enzymes in a cell are proteins.
Carbohydrate
An organic compound composed of carbon based sugars and water.
Lipid
An organic compound composed of a glycerol molecule and 3 fatty acids.
Sugar – Complex Carbs vs Simple
Complex carbohydrates, otherwise known as starches, are chains of 3 or more sugars.
Food sources include grains, breads, cereals, rice, some vegetables and legumes. They
take longer to digest than simple sugars. Simple sugars are made of 2 or less molecules of
sugar. Most, if not all, end in –ose. For example: Glucose; Maltose; Sucrose; Fructose.
Food sources include candies, sodas, syrups, fruits and yogurts.
Energy – Kinetic, Potential
Kinetic energy is how much force an object has in motion. It is based on mass and
acceleration. Potential energy is how much energy an object has at rest. It is based on
mass and position in a gravitational and/or magnetic field and/or concentration gradient.
Matter
Matter is anything that takes up space and has mass.
Abiotic vs biotic
Matter is broken into two categories. Abiotic is matter that is non living. Biotic is living.
Molecule
A combination of two or more atoms.
Atom
The basic unit of matter; consisting of a nuclear region of neutrons and protons and one
or more electrons that orbit the nuclear region. Atoms were once thought to be the
smallest particles of the universe until the study of subatomic particles began in the latter
half of the twentieth century.
Element
A substance that can not be broken down into any other. It is made of only one specific
Type of atom. Pure gold possesses only gold atoms. Pure carbon has only carbon atoms.
Covalent Bond
A bond between atoms where a sharing of electrons occurs.
Exothermic
Exo – Exterior/Out
Thermic – Heat This is a type of reaction where energy is given
off in the form of heat. Will result in a temperature increase. Example: Metal with Acid
Endothermic
Endo – Interior/In
Thermic – Heat
This is a type of reaction where energy is
taken in and stored in the new chemical bonds between the atoms. Will result in a
temperature decrease. Example: Ammonia Nitrate with water.
Calorie
A measurement of energy. One calorie is exactly enough energy to raise the temperature
of one milliliter of water one degree celcius. Food labels usually list calories with a
capital C indicating kilocalories.
Mass
The quantity of inertia an object possesses. Mass and weight are often confused. Mass
Does not change like weight does when an object is subject to different gravitational
forces. You do not weigh the same on the Earth as you do on the moon, but your mass
remains the same.
Density
An object’s mass divided by its volume. Water has a density of 1g/cm 3.
Heterotroph
An organism that can not create its own food and most rely on consuming other
organisms that can create their own food, or energy source for carrying out its
Metabolic functions.
Autotroph
An organism that can create its own food source.
Photosynthesis
A cellular process carried out by most plants and some bacteria which captures light
energy and uses it in combination with carbon dioxide and water to create glucose,
releases oxygen as a waste product.
Cellular Respiration
Another cellular process carried out by all cells. A series of chemical reactions which
break down food molecules (glucose) and obtain energy (ATP) from them.
ATP – Adenosine Triphosphate
A molecule that is used to store energy in living organisms. One adenosine combined
with three phosphates. The bond between the third phosphate and the adenosine is broken
when the organism wants to use that release of energy for any metabolic function.
pH
A measure of acidic a solution is. The scale is 0 – 14. 7 is neutral. Below 7 is acidic.
Above 7 is alkaline, or basic.
Food Pyramid
A guide used by humans to base their diet on.
Food Web
Food chains in an ecosystem taken collectively, showing partial overlapping and
competition for many food organisms.
Producer
An autotroph. Any organism that produces its own food using matter and energy from the
nonliving world.
Consumer
A heterotroph. Any organism that feeds on another organism or their organic wastes.
Decomposer
An organism that lives on decaying organic material, from which it obtains energy and its
own raw materials for life.
Aerobic
Any process that takes place in the presence of oxygen.
Anaerobic
Any process that takes place in the absence of oxygen.
Glycolysis
The first stage in cellular respiration, this is the initial breakdown of a carbohydrate,
usually glucose, into smaller molecules. It requires 2 ATP, but produces 4, thus providing
a net gain of 2 ATP. It is an anaerobic process.
Krebs Cycle
The second, or intermediary, stage in cellular respiration that completes the breakdown of
intermediate products of glycolysis. It is an aerobic process.
Electron Transport System
The process by which electrons are transferred from one carrier molecule to another in
photosynthesis and cellular respiration resulting in the formation of many ATP
molecules. This is an aerobic process.
Chloroplast
This organelle, found only in plants and photosynthetic protists, contains the pigment
chlorophyll which absorbs light energy used to drive photosynthesis.
Thylakoid
A flattened sac in the chloroplast. Many are organized into stacks called grana. The
pigments and enzymes for the light reactions of photosynthesis are embedded in the sac
membrane.
Chlorophyll
The green pigments of plants and many microorganisms; converts light energy to
chemical energy that is used in biological reactions.
Ecosystem
A biological community in its abiotic environment.
Community
All the organisms that inhabit a particular area.
Biomass
The dry weight of organic matter that makes up a group of organisms in a particular
habitat. The total mass of all living material in a habitat.
Habitat
The place where an organism lives.
Niche
The role or function an organism has in its habitat and ecosystem.
Nutrient
Any substance consumed by an organism that will provide for the metabolic functions of
that organism. Human’s six nutrients are classified as water, minerals, vitamins, proteins,
carbohydrates, and lipids (fats).
Toxins
Any substance that eventually causes diminished performance or decreased health.
Mitochondria
An organelle known as the “power house” of the cell because it is the site of aerobic
respiration. It has an inner and outer membrane.
Major Concepts:
Performance, Fitness and Nutrition
What is your personal definition of fitness? Nutrition and diet affect performance and
fitness. What you eat and the type of lifestyle you live directly affect your ability to
perform physically and mentally.
Conservation of Energy
Energy can neither be created nor destroyed. Even though the amount of energy at one
location can change, the total amount of energy in the universe remains the same.
Conservation of Mass
Matter can neither be created nor destroyed. Matter can change in form and location, but
the total amount of matter in the universe remains the same.
Molecules, Atoms and bonds
Atoms form bonds with one another to create molecules. Bonds are formed when
electrons from the outer orbits of atoms are shared or given, or create an attraction
between positively and negatively charged particles.
Cycles
Matter seems to go through cycles on the Earth, in our solar system, and even in the
universe. Some specific cycles that are fundamental to life on Earth are: Water Cycle;
Carbon Cycle; Nitrogen Cycle.
Photosynthesis
Certain organisms (plants, cyanobacteria, and photosynthetic protests) can capture light
energy and use it to ultimately create food that can be used by their own organism or
other organisms that may consume them. Light energy, carbon dioxide and water are
needed for the organism to produce glucose and ATP. Oxygen is given off as a waste
product. The entire process is divided into two distinct stages; the light dependent and the
light independent stages. The first stage occurs in the presence of light; light energy is
absorbed and then converted into chemical energy. The second stage incorporates carbon
(from carbon dioxide) into carbohydrates (sugars).
Cellular Respiration
All cells are thought to engage in this process in order to provide energy for the
organism. The production of ATP molecules is the ultimate goal. There are three major
steps. The first one is anaerobic, meaning it does not require oxygen. It is called
glycolysis. It takes place in the cytosol and is the initial breakdown of glucose. It
produces a net gain of 2 ATP. The second two steps are both aerobic. The Krebs Cycle
takes the pyruvate molecules from glycolysis and uses them to synthesize a six carbon
compound from acetyl CoA and oxaloacetate. The six carbon sugar citrate then goes
through a series of reactions which eventually release two molecules of carbon dioxide,
some ATP and several NADH molecules (energy carriers).
Energy pyramids and trophic levels
Energy is passed on from organism to organism in a community. However, only a portion
the energy available at one trophic level is available at the next higher trophic level. This
is a key argument for convincing people to eat lower on the food web. To explain this,
let’s use the example of the grass, cow and human. If a person were to only eat meat
(cows), it would take 100 kg of plants (grass eaten by the cow) to create 1 kg of human
biomass. If the person were to eat the grass directly, it would only take 10 kg of food to
create that same 1 kg of human biomass.