BIO Quiz #1


To allow internal physiological conditions to vary with environmental conditions (Poikilotherm/Heterotherm)


An animal whose internal temperature varies with the environmental temperature


An animal who maintains their internal temperature within a narrow range

Countercurrent exchanger

Transfer heat between fluids flowing in opposite directions reduces heat lossMaximizes exchange


An animal that gains most of its body heat from external sources


Change something ex. body temperature to return to set point


An animal that gains most of its body heat from internal metabolic processes


Stability in the chemical and physical conditions within an organismEx. temp, pH, blood sugar, osmolarity, body water level...

Integrator (Control Center)

Receives signal, decides what action needs to be taken, signals to effectors

Negative Feedback

A change in variable triggers a response that counteracts the initial fluctuation-Response shuts off as variable returns to set pointUsed to maintain homeostasis

Positive Feedback

Change in a variable triggers mechanisms that further amplify the change in the same directionNOT used in homeostasis because it makes small changes larger


To actively maintain relatively constant internal conditions even when the environment fluctuates (Homeotherm)


Physiological activity that helps return variable to set point


Detects change in internal environment (receptor)

Set Point

A normal range of values for the variable


Fluctuations above/below the set point

Surface Area/Volume Ratio

Surface area increases while the volume remains the same


Thermogenesis- Adjustment of metabolic heat production to maintain body temperature-increased by muscle activity (moving, shivering)-Non-shivering-thermogenesis- Takes place when hormones cause mitochondria to increase their metabolic activity


Blood vessels restrict flow of blood


Blood vessels enlarge to allow more blood volume to flow

Define homeostasis and explain why it is important

Stability in the chemical and physical conditions within an organismEx. temp, pH, blood sugar, osmolarity, body water level...Important because it regulates the body and keeps things constant

Describe necessary exchanges between the organism and the environment


Explain the role of exchange with the environment in maintenance of homeostasis

Radiation- Transfer of heat between two bodies that are not in direct physical contactEx. sunbathingConvection- Transfer of heat by movement of air or liquid past a surfaceEvaporation- A removal of heat from a surface of a liquid as it goes through a phase change to gasConduction- Direct transfer of heat between two bodies that are in direct physical contact with each other

Describe how changes to a physiological variable can initiate a response leading to either positive or negative feedback.

Negative FeedbackA change in variable triggers a response that counteracts the initial fluctuation-Response shuts off as variable returns to set pointPositive FeedbackChange in a variable triggers mechanisms that further amplify the change in the same direction

Differentiate between positive and negative feedback

Negative feedback is used to maintain homeostasisPositive feedback is NOT used in homeostasis because it makes small changes larger

Describe thermoregulation in animals as an example of homeostasis and describe the physiological responses (e.g., shivering, sweating, vasoconstriction, vasodilation, countercurrent exchange)

5 adaptations help animals thermoregulate:1. Insulation2. Cooling by evaporation heat loss3. Behavioral responses4. Circulatory adaptations5. Adjusting metabolic heat productionVasoconstriction*Blood vessels restrict the flow of bloodVasodilation*Blood vessels enlarge to allow more blood volume to flowCountercurrent exchangerTransfer heat between fluids flowing in opposite directions reduces heat lossMaximizes exchange

Sweating (vasodilation)


Shivering (vasoconstriction)


Describe what is meant by the relationship between form and function


Explain the surface area/volume ratio in a way that affects exchange with theenvironment


Explain how the surface area/volume ratio is affected by folding, branching and flattening and how this leads to an increased capacity for exchange with the environment.



Chainlike molecules made up of monomers, also known as a polymer4 Macromolecules of the Cell:1. Protein2. Nucleic Acids3. Carbohydrates4. Lipids

Adenosine triphosphate (ATP)

A specialized nucleotide that is the energy currency of the cell. The high energy phosphate groups represent stored energy that can be released in a chemical reaction.ATP is made up of:1. Ribose sugar2. Nitrogenous base adenine3. 3 phosphate groups

Amino Acid

Any of a group of organic molecules that consist of a basic amino group (―NH2), an acidic carboxyl group (―COOH), and an organic R group (or side chain) that is unique to each amino acid.


Chemical that speeds up a reaction to allow it to occur more quickly-lowers the energy of activation-is not altered in the reaction

Activation Energy (EA)

energy needed to get a reaction started

Dehydration reaction (condensation reaction)

Used to build a polymer-water is removed to form a new bond-enable amino acids (monomers) to be linked together to form a polypeptide (polymer)

Endergonic Reaction

Reaction in which the reactants have less energy than the products-energy is required


An organic molecule that functions as a catalystEx. proteins, sometimes RNA

Exergonic Reaction

Reaction in which the reactants have more energy than the products (exothermic)-energy is released

Hydrogen Bond

Interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces. Hydrogen bonds can exist between atoms in different molecules or in parts of the same molecule.-Hydrogen bonds join complementary base pairs C-G pairs have 3 hydrogen bonds, A-T pairs have 2


A double decomposition reaction with water as one of the reactants.


Water loving" substance with affinity for water-includes ions and polar molecules-interact with other ions and molecules


Any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions.


Water fearing" substance with no affinity for water-uncharged and nonpolar only want to interact with eachother


An individual unit of a polymer

Non-polar Molecules

No separation of charge, so no positive or negative poles are formed.-electrons are equally shared-hydrophobic


Any member of a class of organic compounds in which the molecular structure comprises a nitrogen-containing unit (base) linked to a sugar and a phosphate group. The nucleotides are of great importance to living organisms, as they are the building blocks of nucleic acids, the substances that control all hereditary characteristics.

Nucleic Acid

Polymers made up of nucleotides (monomers)-hydrophilic-store, transmit, express hereditary info


Stands for inorganic Phosphate. It is comprised of four oxygen atoms bonded covalently to a phosphorous atom.


The chemical addition of a phosphoryl group (PO3-) to an organic molecule


The distribution of electrical charge over the atoms joined by the bond

Polar Molecules

Electrons are not shared equally and result in partial charges (partial positive and partial negative pole)


Large molecule, or macromolecule, composed of many repeated subunits


1 or more polypeptides with 3D structure


polymer made up of amino acids (monomer)-R-group can make stretches Hydrophilic or Hydrophobic-Greater than or equal to 50 amino acids

Understand how the structure of water molecules relates to the functions of water (e.g. interactions with other molecules, including hydrogen bonding).


Describe how the charge, polarity, or lack of polarity of a molecule affects its interactions with water (i.e. what makes a molecule hydrophobic or hydrophilic)

Water is polar covalently bonded within the molecule. This unequal sharing of the electrons results in a slightly positive and a slightly negative side of the molecule. Polar molecules (with +/- charges) are attracted to water molecules and are hydrophilic. Nonpolar molecules are repelled by water and do not dissolve in water; are hydrophobic

Identify the major biological monomers of proteins and nucleic acids

Monomers are the building blocks of the four basic macromolecules of life- monosaccharides are the monomers of carbohydrates, amino acids are the monomers of proteins, glycerol/fatty acids are the monomers of lipids, and nucleotides are the monomers of DNA.

Differentiate between the roles of dehydration reactions and hydrolysis in the synthesis and breakdown of proteins and nucleic acids

Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy. Carbohydrates, proteins, and nucleic acids are built up and broken down via these types of reactions, although the monomers involved are different in each case.

Recognize the structure of amino acids


Recognize the structure of nucleotides


List the four levels of protein structure.

1. Primary structure- the amino acid sequence2. Secondary sequence- local patterns found within a proteinAlpha-helices- coils like a telephone poleBeta-sheets- amino acids line up side by side3. Tertiary Structure- complete folding of polypeptideHolding it together are:Hydrogen BondsIonic BondsVan Der Waals Forces between nonpolar Amino AcidsDisulfide Bridges: covalent bonds between Cysteine amino acids4. Quaternary Structure- multiple polypeptides can come together as subunits to make a larger functional protein-NOT all polypeptides for larger proteins with Quaternary structure

Describe functions associated with proteins.

1. Enzymatic proteins- selective acceleration of chemical responsesEx. digestive enzymes2. Defensive proteins (immune)- protection against diseaseEx. antibodies3. Storage proteins- storage of amino acidsEx. casein, ovalbumin4. Transport proteins- transport of substancesEx. hemoglobin- transport oxygen5. Hormonal proteins- coordination of an organism's activitiesEx. insulin6. Receptor proteins- response of cell to chemical stimuliEx. neurotransmitter receptors7. Contractile and Motor proteins- movementEx. actin and myosin8. Structural proteins- supportEx. keratin, collagen

Understand the basics of how enzymes catalyze reactions by lowering activation energy.


Recognize the structures of nucleic acids

3 components:1. Nitrogenous Base (C-Cytosine, U-Uracil, T-Thymine, G-Guanine, A-Adenine)2. 5-Carbon sugar3. Phosphate Group

Describe the functions associated with each type of nucleic acids (RNA and DNA)

DNA- carrier of genetic informationThe sugar-phosphate backbone is charged due to the negative phosphate groups faces outwards and gives DNA its hydrophilic propertiesThe bases are nonpolar and hydrophobic and cause the molecule to twist into a helixRNA- act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information.RNA differs from DNA:1. Ribose sugar2. Replaces Thymine with Uracil3. Single-stranded4. Can fold and behave like enzymesTypes of RNA:mRNA (messenger RNA)- made to match the sequence in DNA during transcription, then is read during translation (making a protein)tRNA (transfer RNA)rRNA (ribosomal RNA)- major component of Ribosomes

Describe the role of ATP in cellular processes (endergonic reactions, phosphorylation.)


Polypeptide Formation

To make a polypeptide, amino acids become covalently bonded (peptide bond) through dehydration synthesis

Need to know