Virginia Tech BMSP 2135 RAT #3 2.3-2.5

*this type of reaction* can progress in both the forward and reverse directions; two arrows pointing in opposite directions between reactants and products indicates this reaction type

reversible reactions

this type of energy is energy that is stored, ready to be released and used to do work

potential energy

potential energy become *this type of energy* when it is used; energy in motion, which means that work of some sort is being done

kinetic energy

*Three Forms of Potential Energy in Human Body*

1. ______________ energy: drives nearly all our cellular processes; energy inherent in chemical bonds

chemcial

*Three Forms of Potential Energy in Human Body*

2. ______________ energy: generated by movement of charged particles; in our cells, this energy results from flow of electrons

electrical

*Three Forms of Potential Energy in Human Body*

3. ______________ energy: energy that has been directly transferred from 1 object to another; example: when the tiny proteins in muscles move past one another and generate a muscle contraction, they transfer this energy first to the muscle cell, then to the whole muscle, and finally to the body part that moves

mechanical

we shiver when our body temperature drops, a process that converts chemical energy into _________________ energy that moves our muscles cells

much of the chemical energy is lost as heat, and the heat raises our body temperature

mechanical

*this type of reaction* requires an input of energy that is greater than the energy of the reactants

requires chemical, electrical, or mechanical energy from another source to proceed

endergonic

the products of an endergonic reaction contain (more/less) energy than the reactants because energy was invested in the reaction

more

*this type of reaction* is where the reactants have more energy than is needed for the reaction to proceed, so the excess energy stored in reactants is released, leaving the products of the reaction with (more/less) than the reactants

exergonic, less

*3 types of chemical reactions that take place in the human body*

1. ______________ reactions break down chemical bonds

- also called decomposition reaction

- larger substances are broken into smaller ones

catabolic

*3 types of chemical reactions that take place in the human body*

AB → A + B represents which type of chemical reaction?

catabolic

*3 types of chemical reactions that take place in the human body*

catabolic reactions are required to break down nutrients in the foods we eat, to break apart and recycle old or damaged cells, to defend the body against pathogens, etc.

catabolic reactions are generally _________________ because chemical bonds are broken

exergonic

*3 types of chemical reactions that take place in the human body*

2. _____________ reactions involve the transfer of atoms or electrons between reactants; one or more atoms from the reactants are exchanged for another; bonds are broken and formed

exchange

*3 types of chemical reactions that take place in the human body*

AB + CD → AD + BC represents what type of chemical reaction?

exchange reaction

*3 types of chemical reactions that take place in the human body*

a special type of exchange reaction is the oxidation-reduction reaction where ____________ are exchanged, not atoms

electrons

*3 types of chemical reactions that take place in the human body: redox reactions*

the electrons exchanged in a redox reaction carry energy with them

exchange reactions are generally _______________ and can release large amounts of energy

exergonic

*3 types of chemical reactions that take place in the human body*

3. _______________ reactions form new chemical bonds; also called synthesis reactions

A + B → AB

anabolic

*3 types of chemical reactions that take place in the human body*

anabolic reactions are generally ________________, and they are fueled by chemical energy

endergonic

*This* is the energy required to overcome the repulsion of the atoms' electrons and to allow adequately strong collisions to occur; all reactions (even exergonic) must overcome this energy barrier

activation energy (Ea)

Factors that increase rate of reactions

1. increase in [reactant]

2. increase in reactant ___________________

3. smaller particles and gaseous phase (d.t. higher kinetic energy)

4. presence of a catalyst (substance that increases reaction rate by lowering Ea)

temperature

_____________ = biological catalysts

enzymes

_________ is the suffix most commonly used when naming enzymes

-ase

nearly all enzymes are macromolecules called ________________

proteins

*Role of Enzymes in Body*

1. involved in almost all catabolic reactions, as well as some exchange and anabolic reactions

2. without enzymes, the chemical reactions required to carry out all our basic processes to maintain _______________ would occur far too slow for us to remain alive

homeostasis

*Properties of Enzymes*

1. speed of reactions by lowering Ea

2. highly specific for individual substrates and reactions

3. (do/do not) alter the chemical reaction

4. not permanently altered in the reaction

do not

*Properties of water*

water absorbs heat without changing significantly in temperature itself

- water's *what* = a large amount of heat must be applied to disrupt enough hydrogen bonds to change water from a liquid to a gas

- water must be heated to 100 degrees Celsius/212 degrees Fahrenheit to boil

high heat capacity

*Properties of water*

water carries __________ with it when it changes from a liquid to a gas

- sweat will start to evaporate when enough heat is available to disrupt the hydrogen bonds between water molecules

- this heat is provided by your body, which means in essence that the water pulls heat out of your body when it turns into water vapor

heat

*Properties of water*

water cushions and protects the body's structures

- water has high ___________ because the hydrogen bonds pull water molecules closely together so that they occupy less space

- most of the body's organs are less dense that water, so they are able to remain slightly suspended in their watery surroundings, which is important for organs like the brain

density

*Properties of water*

water acts as a _____________ between 2 adjacent surfaces

- reduces friction

- functions in this way in the serous membranes surrounding the lungs, the heart, and the abdominal organs

lubricant

water is a good solvent for living organisms because of its molecule shape (bent with 2 H atoms at an angle to each other) and its polar covalent bonds

many solutes vital to homeostasis are _______________

hydrophilic

_______________ is a property of substances with partially or fully charged ends (polar covalent and ionic compounds) that will dissolve when placed in water

hydrophilic

__________________ is a property of substances with no dipole (nonpolar covalent bonds) that will not dissolve when placed in water

examples: methane, fats, oils, oxygen, CO2

hydrophobic

The study of acids and bases is really the study of the .....

hydrogen ion

hydrogen behaves like a ______________ most of the time, forming covalent rather than ionic bonds, and elemental hydrogen exists on Earth as a gas, not a metal

nonmetal

an acid = a hydrogen ion __________; pH

donor

base = H+ ion _____________; pH>7

acceptor

equation for pH

*pH scale*

* 0-14

* acidic → basic (alkaline)

* _____________ = # of H+ ions and base ions in solution is equal

neutral

the ______________ the H+ ion concentration, the higher the pH

smaller

______________ keep the pH of the body's fluids within normal ranges by resisting changes in pH and preventing large swings in the pH when acid or base is added to a solution

buffers

the 2 main organs systems in the body that work to correct pH imbalances are the ________________ and ____________ systems

respiratory, urinary

a(n) ___________ is any metal cation and nonmetal anion held together by ionic bonds; will dissolve when placed in water

salt

________________ are the resulting cations and anions in solution when ionic compounds dissolve; these ions will conduct an electrical current in water

electrolytes

all salts dissociate into ________________, and so do some acids and bases

electrolytes

_____________________ are single subunits that can be combined to build larger structures

monomers

__________________ are larger structures that consist of many monomers linked together chemically by dehydration synthesis

polymers

carbo- means

carbon

-hydrate means

water

carbohydrates have the ratio of __C:___H:___O

1,2,1

*Function of Carbohydrates in Human Body*

1. fuel: catabolic and redox reactions liberate the chemical energy stored in the bonds of carbs and use it to drive the synthesis of the nucleotide ______, which is the main source of chemical energy

2. structural roles: some carbohydrates are scattered throughout the membranes that surround our cells

ATP

the monomer of carbohydrates =

monosaccharide (simple sugar)

monosaccharides have from 3-7 carbon atoms, generally are in ring structure, majority in body are pentoses or hexoses

the primary pentose sugars are *what*

deoxyribose, ribose

the main monosaccharide in the body is ______________

glucose

the 2 most prevalent disaccharides in the body are *what*

sucrose, lactose

disaccharides are formed via *what*

dehydration synthesis (hydrogen atom is removed from fructose and a hydroxyl group -OH is removed from glucose, forming a water molecule)

when a disaccharide undergoes hydrolysis, what forms?

two monosaccharides

a _______________ is a polymer that is the largest of the carbohydrates that are composed of long, branching chains of monosaccharides joined by covalent bonds that were formed by dehydration synthesis; composed of polar, hydrophilic monomers; not very soluble in water

polysaccharide

___________ is the polysaccharide plants store their glucose as

starch

____________ is the polysaccharide animals store their glucose as; primarily found in liver and skeletal muscles

glycogen

lipids are typically ______________ because of the predominance of carbons and hydrogens in their structure, making them overall very nonpolar

hydrophobic

monomer of lipids is the

fatty acid

fatty acids have a carboxylic acid group (___________) bonded to a hydrocarbon chain that can have 4-20 or more carbon atms

-COOH

a _______________ fatty acid has no double bonds, found predominantly in animal fats, and they are mostly solid at room temp

saturated

____________________ FAs have a lower melting point than saturated fats, so they are generally liquid at room temperature

monounsaturated

__________________ FAs have MPs that are lower than those of both saturated and monosaturated fatty acids, and they are liquid at room temperature

polyunsaturated

our bodies cannot package FAs into long chains as they can monosaccharides, so instead FAs are stored by linking 3 of them via dehydration synthesis to a modified 3-carbon sugar called a _____________ to produce a polymer called a neutral fat or _________________

glycerol, triglyceride

triglycerides are stored in fat cells, where they help to insulate our internal organs against physical shock and regulate body temperature

triglycerides are also a ready supply of ________

fuel

_________________ have a glycerol backbone, 2 FAs, and a phosphate group

phospholipids

in a phospholipid, the phosphate head is very polar and the hydrophilic

the fatty acid tails are very nonpolar and ___________________

hydrophobic

phospholipids serve as the main structural components of _________ _______________, the barriers between our cells and their environment

cell membranes

_____________ are a class of lipids that all share a four-ring hydrocarbon structure called the steroid nucleus attached to other chemical groups

steroids

______________ forms the basis for the body's other steroids, including bile acids that function in digestion and the sex hormones estrogen and testosterone

cholesterol

*Protein functions*

· _____________

· play vital structural roles

· function in body's defenses

· allow cells to communicate

· make muscles contract

· can be oxidized as fuel

enzymes

the monomer of a protein is the

amino acid

a __________ is the protein polymer consisting of 2 or more AAs joined via a peptide bond (polar covalent bond) via dehydration synthesis

peptide

all AAs share the same core structure made of CHON atoms

each has a central carbon atom bonded to 4 chemical groups

1. a hydrogen atom

2. N containing amino group (NH2)

3. a carboxylic acid group (-COOH)

4. another atom or group of atoms (____ __________)

R group

a protein must maintain structure to be ________________; denaturation destroys protein's shape

functional

protein primary structure = ___________ _________ _________ of its polypeptide

amino acid chain

protein secondary structure: folding one or more segments of the polypeptide over on itself; 2 common patterns: alpha helixes and beta-pleated sheets, which are both stabilized by ___________ _________ between AAs

hydrogen bonds

protein tertiary structure: final 3-dimensional shape it assumes; twists, folds, coils that form between and around the alpha helices and beta sheets; stabilized by hydrogen bonds and ionic interactions that occur between the ___ ____________ of the AAs in polypeptide chain

R groups

protein quaternary structure: structure that arises for proteins with more than 1 ____________________ __________

polypeptide chain

3 parts of a nucleotide = nitrogenous base, ____________ sugar, phosphate group(s)

nitrogenous bases are either purines or pyrimidines

pentose

ATP structure: adenine nitrogenous base attached to ___________ sugar, which is attached to 3 phosphate groups

ribose

ATP is synthesized by adding a third phosphate to ADP; through catabolism of organic compounds, primarily ____________

glucose

ATP hydrolysis = ATP can be hydrolyzed to ADP and Pi by the addition of ________, releasing energy (exergonic reaction)

water

DNA and RNA = _________ _______ = polymers of linked nucleotides

nucleic acids