Chemistry of Life

1
Chemistry of Life

• Chapter 2

2
Introduction to Biochemistry

• Biochemistry is the study of structure,
  composition (what things are made up of), and
  chemical reactions that occur in living things.
• Living things (biotic factors) depend on
  chemistry to carry out life processes, so biology
  and chemistry are closely related!

3
AKS Standards 8e - identify the elements that
comprise living cells
4
Living things consist of atoms of different
elements.

• Matter is anything that has mass or takes up
  space.
• Matter is made up of small units called atoms.
• Atoms are made up of 3 subatomic particles
• Protons (which have a charge)
• Electrons (which have a charge)
• Neutrons (which have no charge)
• Together these substances help form matter!

5
Elements

• When atoms of the same type come together they
  make up units called elements. Elements cannot
  be broken down into simpler substance by ordinary
  chemical means.
• An element is a pure substance made of only 1
  type of atom (it is usually abbreviated by a
  chemical symbol)

6
Chemical Compounds

• Remember that elements are made up of small units
  called atoms. When these elements come in close
  contact with each other, they often have an
  attraction like magnets.
• The attraction of these elements often leads to a
  bond the joining of atoms to one another.
• When two or more elements are put together, they
  form a chemical compound.
• These compounds are usually represented by a
  chemical formula a combination of chemical
  symbols that represent the joining of these
  elements.
• Examples NaCl (salt) H2O (water) CO2
  (carbon dioxide)

7
Chemical Bonds

• The atoms in compounds are held together by
  chemical bonds.
• Bond formation involves the electrons that
  surround each atomic nucleus.
• Electrons that are available to form bonds are
  called valence electrons.
• The main types of chemical bonds are ionic bonds
  and covalent bonds.

8
Ionic Bonds

• An ionic bond is formed when one or more
  electrons are transferred from one atom to
  another
• An atom that loses electrons is no longer
  neutral, instead it becomes positively charged.
• An atom that gains an electron is no longer
  neutral, instead it becomes negatively charged.
• These positively and negatively charged atoms are
  called ions.

9
Covalent Bonds

• Sometimes electrons are shared by atoms instead
  of being transferred
• These electrons are located in a region between
  the atoms.
• A covalent bond forms when electrons are shared
  between atoms.
• The structure that results when atoms are joined
  together by covalent bonds is called a molecule
  (this is the smallest unit of most compounds).

10
Review Ionic Covalent Bonds
IONIC BONDS electrons are transferred between
atoms
COVALENT BONDS electrons are shared between atoms
11
Interactive review Chemistry of Life

• http//www.classzone.com/cz/books/bio_07/resources
  /htmls/interactive_review/bio_intrev.html

Complete this interactive review using your
virtual textbook at home. Concept maps are an
excellent way to organize your thoughts and
review material!
12
AKS Standards 8f - explain the impact of water in
life processes (e.g., adhesion, cohesion,
capillarity, density, and osmosis) GPS)
13
Life depends on hydrogen bonds in water.

• Water is the most abundant compound in living
  things.
• Some of waters properties that facilitate an
  environment for life are
• Cohesive and adhesive behavior
• Ability to moderate temperature (high specific
  heat)
• Expansion upon freezing
• Versatility as a solvent
• http//www.sumanasinc.com/webcontent/animations/co
  ntent/propertiesofwater/water.html

14
Polarity Hydrogen Bonding in Water

• The water molecule is a polar molecule the
  opposite ends have opposite charges.
• Water is polar because the oxygen atom has a
  stronger electronegative pull on shared electrons
  in the molecule than do the hydrogen atoms.
• Polarity allows water molecules to form hydrogen
  bonds with each other. These are weak covalent
  bonds.

15
Cohesion Adhesion

• Collectively, hydrogen bonds hold water molecules
  together, a phenomenon called cohesion
• Cohesion is the attraction of molecules of like
  substance.
• Cohesion due to hydrogen bonding contributes to
  the transport of water and dissolved nutrients
  against gravity in plants.
• Adhesion is the clinging of one substance to a
  different substance
• In other words, water molecules stick to other
  things.
• Adhesion of water to cell walls by hydrogen bonds
  helps to counter the downward pull of gravity on
  the liquids passing through plants.

16
Adhesion
Water-conducting cells
Direction of water movement
Cohesion
150 µm

• Cohesion and adhesion work together to give
  capillarity the ability of water to spread
  through fine pores or to move upward through
  narrow tubes against the force of gravity.

17
Surface Tension

• The high surface tension of water, resulting from
  the collective strength of its hydrogen bonds,
  allows the water strider to walk on the surface
  of the pond.
• Surface tension is directly related to the
  cohesive property of water it is a measurement
  of how difficult it is to stretch or break the
  surface of a liquid.

18
Moderation of Temperature

• Water can absorb or release a large amount of
  heat with only a slight change in its own
  temperature. The ability of water to stabilize
  temperature results from its relatively high
  specific heat
• This is the amount of heat that must be absorbed
  or lost for 1g of a substance to change its
  temperature by 1C.
• Hydrogen bonds give water an abnormally high
  specific heat, and water therefore resists
  changes in temperature.
• Waters high specific heat can be traced to
  hydrogen bonding. Heat is absorbed when hydrogen
  bonds break, and heat is released when hydrogen
  bonds form.
• The high specific heat of water is due to
  hydrogen bonding. H-bonds tend to restrict
  molecular movement, so when we add heat energy to
  water, it must break bonds first rather than
  increase molecular motion.

19
Evaporative Cooling

• Evaporation is transformation of a substance from
  liquid to gas. Heat of vaporization is the heat
  a liquid must absorb for 1 g to be converted to
  gas. As a liquid evaporates, its remaining
  surface cools, a process called evaporative
  cooling.
• The high amount of energy required to vaporize
  water has a wide range of effects
• Helps stabilize temperatures in organisms and
  bodies of water.
• Evaporation of sweat from human skin dissipates
  body heat and helps prevent overheating on a hot
  day or when excess heat is generated by strenuous
  activity.

20
The Density Anomaly

• Ice floats in liquid water because hydrogen bonds
  in ice are more ordered, making ice less dense.
• If ice sank, all bodies of water would eventually
  freeze solid, making life impossible on Earth.

21
The Solvent of Life

• Water provides living systems with excellent
  dissolving capabilities.
• A solution is a liquid that is a homogeneous
  mixture of substances
• Solvent (dissolving agent)
• Solute (substance that is dissolved)
• An aqueous solution is one in which water is the
  solvent.

22
Hydration Shellhttp//www.sumanasinc.com/webconte
nt/animations/content/propertiesofwater/water.html

• A hydration shell refers to the sphere of water
  molecules around each dissolved ion in an aqueous
  solution. Water will work inward from the
  surface of the solute until it dissolves all of
  it (provided that the solute is soluble in water).

If a spoonful of salt (or other ionic substance)
is placed in water, the ions in the salt and the
water molecules have a mutual affinity owing to
the attraction between opposite charges. O is
negative and attracts to positive sodium. H is
positive and attracts to negative chlorine. As a
result, water will surround the individual sodium
and chloride ions, separating and shielding them
from one another (called a hydration
shell). WATER IS THE SOLVENT OF LIFE molecules
within a living system must be broken down in
order to be used by the system!
23
Acids and Bases

• An acid is any substance that increases the H
  concentration of a solution.
• A base is any substance that reduces the H
  concentration of a solution.
• A solutions acidity, or H ion concentration, is
  measured by the pH scale.

24
pH Scale
0
1
Battery acid
Gastric juice, lemon juice
2
H
H
H
Vinegar, beer, wine, cola
OH
H
3
H
OH
Increasingly Acidic H gt OH
H
H
H
4
Tomato juice
Acidic solution
Black coffee
5
Rainwater
6
Urine
OH
Saliva
OH
Neutral H OH
7
Pure water
OH
H
H
OH
OH
Human blood, tears
H
H
H
8
Seawater
Neutral solution
9
10
Increasingly Basic H lt OH
Milk of magnesia
OH
OH
11
OH
OH
H
Household ammonia
OH
OH
OH
H
12
Basic solution
Household bleach
13
Oven cleaner
14
25
Buffers

• One way pH is regulated in organisms is by
  substances called buffers.
• A buffer is a compound that can bind to an H ion
  when the H concentration increases, and can
  release H ion when the H concentration
  decreases.
• In other words, buffers lock up H ions and
  help to maintain homeostasis.
• Most buffers consist of an acid-base pair that
  reversibly combines with H
• CO2 H2O ? H2CO3 ? HCO3- H

26
Critical Thinking Activities Compare
ContrastConnecting Concepts

• How do polar molecules differ from non-polar
  molecules? How does this difference affect their
  interactions?
• When sugars are broken down to produce usable
  energy for cells during cellular respiration, a
  large amount of heat is released. Explain how
  the water inside a cell helps to keep the cells
  temperature constant.
• Polar molecules have charged regions due to
  unequal sharing of electrons. Nonpolar molecules
  do not have charged regions because electrons
  are shared more equally. The charge differences
  tend to keep the molecules separate.
• Water has a high specific heat water in a cell
  can absorb a large amount of energy before its
  temperature changes.

27
Interactive review Properties of Water

• http//www.classzone.com/cz/books/bio_07/resources
  /htmls/interactive_review/bio_intrev.html

Complete this interactive review using your
virtual textbook at home. Concept maps are an
excellent way to organize your thoughts and
review material!
28
AKS Standards 8k - describe the four basic types
of organic macromolecules (carbohydrates, lipids,
proteins, and nucleic acids) and their function
in the cell (GPS)
29
Carbon atoms have unique bonding properties.

• Carbon is often called the building block of life
  because carbon atoms are the basis of most
  molecules that make up living things.
• Carbon is so important because its atomic
  structure gives it bonding properties that are
  unique among elements.
• Each carbon atom has four unpaired electrons in
  its outer energy level.
• Therefore, carbon atoms can form covalent bonds
  with up to four other atoms.

30
Four main types of carbon-based molecules are
found in living things.

• Many of the molecules in living cells are so
  large that they are known as macromolecules.
• They are formed by a process called
  polymerization (making large compounds by joining
  smaller compounds together).
• The smaller unit (building block) is known as
  monomer these join together to form polymers
  (the macromolecule).
• The four groups of organic compounds found in
  living things are
• Carbohydrates
• Lipids
• Nucleic acids
• Proteins
• http//bcs.whfreeman.com/thelifewire/content/chp03
  /0302002.html

31
Formation of Macromoleculeshttp//bcs.whfreeman.c
om/thelifewire/content/chp03/0302002.html

• Monomers are connected into polymers by a
  reaction in which 2 molecules are bonded to each
  other through a loss of a water molecule
• (Called a condensation reaction or dehydration
  reaction) because a water molecule is lost.
• Polymers are disassembled into monomers by
  hydrolysis, a process that is essentially the
  reverse of the dehydration reaction.
• Hydrolysis means to break with water. Bonds
  between monomers are broken by the addition of
  water molecules.

32
The Synthesis and Breakdown of Polymers
As each monomer is added, a water molecule is
removed DEHYDRATION REACTION.
This is the reverse of dehydration is
HYDROLYSISit breaks bonds between monomers by
adding water molecules.
33
Carbohydrates

• Carbohydrates are molecules composed of carbon,
  hydrogen, and oxygen in a 121 ratio (CnH2nOn).
• They include simple sugars and their polymers.
• They can be broken down to provide a source of
  usable chemical energy for cells and they are
  also a major part of plant cell structure.
• Carbs exist as three types
• 1. monosaccharides
• 2. disaccharides
• 3. polysaccharides (macromolecule stage)

34
Monosaccharides

• Monosaccharides are major sources of energy for
  cells!
• Ex. Glucose cellular respiration.
• Monosaccharides are simple enough to serve as raw
  materials for synthesis of other small organic
  molecules such as amino and fatty acids.
• Most common glucose, fructose, galactose.
• Glucose
• made during photosynthesis
• main source of energy for plants and animals
• Fructose
• found naturally in fruits
• is the sweetest of monosaccarides
• Galactose
• found in milk
• is usually in association with glucose or
  fructose

35
Disaccharides

• Disaccharides consist of two monosaccharides
  joined by a glycosidic linkage a covalent bond
  resulting from dehydration synthesis.
• Examples
• Maltose 2 glucoses joined (C12H22O11)
• Sucrose glucose and fructose joined (C12H22O11)
• Lactose glucose and galactose joined (C12H22O11)

36
Examples of Disaccharide Synthesis
37
Polysaccharides

• These are the polymers of sugars the true
  macromolecules of the carbohydrates.
• They serve as storage material that is hydrolyzed
  as needed in the body or as structural units that
  support bodies of organisms.
• Starches, glycogen, and cellulose are examples of
  polysaccharides.

These are polymers with a few hundred to a few
thousand monosaccharides joined by glycosidic
linkages.
38
Storage Structural Polysaccharides

• Starch and Glycogen are storage polysaccharides.
• Starch sugar/energy storage for plants
• Glycogen sugar/energy storage for animals
• Cellulose and Chitin are structural
  polysaccharides
• Cellulose found in cell wall of PLANTS
• Chitin found in cell wall of FUNGI

39
Lipids

• Lipids are a group of macromolecules that does
  not include polymers they are only grouped
  together based on trait of little or no affinity
  for water all lipids are hydrophobic (water
  fearing).
• The hydrophobic nature of lipids is based on
  molecular structure they consist mostly of
  hydrocarbons! Hydrocarbons are insoluble in
  water because of their non-polar CH bonds!
• Lipids are composed of carbon, hydrogen, and
  oxygen (like carbohydrates), but not in a 121
  ratio.
• Lipids serve as energy storage molecules. The
  can also act as chemical messengers within and
  between cells and are major components of
  biological membranes.
• Groups of lipids include
• Fats
• Steroids
• Waxes
• Phospholipids

40
Fats -- Triglycerides

• Triglycerides are made of two kinds of smaller
  molecules glycerol and fatty acids (one
  glycerol to three fatty acids).
• Dehydration synthesis hooks these up 3 waters
  produced for every one triglyceride
• ESTER linkages bond glycerol to the fatty acid
  tails bond is between a hydroxyl group and a
  carboxyl group.
• Fats are used for protection, cushion, and energy
  backup.

41
The Synthesis and Structure of a Fat, or
Triglycerol

• One glycerol 3 fatty acid molecules
• One H2O is removed for each fatty acid joined to
  glycerol
• Result is a fat

42
Saturated v. Unsaturated Fats

• The terms saturated and unsaturated refer to
  the structure of the hydrocarbon chains of the
  fatty acids.
• No double bonds between the carbon atoms of the
  chain means that the maximum of hydrogen atoms
  is bonded to the carbon skeleton (SATURATED).
• THESE ARE THE BAD ONES!!! they can cause
  atherosclerosis (plaque develop, get less flow of
  blood, hardening of arteries)!
• If one or more double bonds is present, then it
  is UNSATURATED.
• These tend to kink up and prevent the fats from
  packing together

43
Examples of Saturated and Unsaturated Fats and
Fatty Acids 
At room temperature, the molecules of an
unsaturated fat cannot pack together closely
enough to solidify because of the kinks in their
fatty acid tails.
At room temperature, the molecules of a saturated
fat are packed closely together, forming a solid.
44
Phospholipids

• Phospholipids are a special kind of lipid that
  have only two fatty acid tails!
• The third hydroxyl group of glycerol is joined to
  a phosphate group (negatively charged)
• Phospholipids are ambivalent to water tails are
  hydrophobic, heads are hydrophilic.
• At the cell surface, phospholipids have a double
  layer arrangement called a phospholipid bilayer.
• Hydrophilic head of molecules are on outside of
  the bilayer, in contact with aqueous solutions
  inside outside cell.
• Hydrophobic tails point toward interior of
  membrane, away from water.

45
The Structure of a Phospholipid
46
Proteins

• Proteins account for over 50 of dry weight of
  cells
• Used for structural support
• storage
• transport
• signaling
• movement
• defense
• metabolism regulation (enzymes)
• Are the most structurally sophisticated molecules
  known
• Are polymers constructed from 20 different amino
  acids

47
(No Transcript)
48
Hierarchy of Structure in Proteins

• Amino acids building blocks of proteins there
  are 20 different amino acids in nature.
• Polypeptides polymers of amino acids.
• Protein one or more polypeptides folded and
  coiled into specific conformations.

49

• All differ in the R-group (also called side
  chain).
• The physical and chemical properties of the
  R-group determine the characteristics of the
  amino acid.
• Amino acids possess both a carboxyl and amino
  group.

50
How Amino Acids Join

• The carboxyl group of one amino acid is joined to
  the amino group of another, dehydration synthesis
  occurs, and a special type of covalent bond
  called a peptide bond forms.
• When repeated over and over, a polypeptide is
  built.

Note this is dehydration synthesis. Note
carboxyl group of one amino acid end attaches to
amino group of another amino acid end. Note
peptide bond is formed. Note repeating this
process builds a polypeptide.
51
A Proteins Function Depends on Its Conformation

• All proteins in nature differ in the number and
  order of amino acids in the polypeptide chains.
  The amino acid sequence determines a proteins
  structure and function.
• Proteins are very sophisticated molecules that
  have four layers of structure
• Primary Structure unique sequence of amino
  acids (long chain)
• Secondary Structure segments of polypeptide
  chain that repeatedly coil or fold in patterns
  that contribute to overall configuration. These
  are the result of hydrogen bonds at regular
  intervals along the polypeptide backbone.
• Tertiary Structure superimposed on secondary
  structure irregular contortions from
  interactions between side chains.
• Quaternary Structure the overall protein
  structure that results from the aggregation of
  the polypeptide subunits.

52
The Four Levels of Protein Structurehttps//myweb
space.wisc.edu/jonovic/web/proteins.html
53
The External Environment Can Affect Protein
Structure

• The polypeptide chain of given amino acid
  sequence can spontaneously arrange into 3-D
  shape.
• This configuration also depends on physical and
  chemical conditions of proteins environment.
• If pH, salt , temp, etc. are altered, protein
  may unravel and lose native conformation this
  process is called denaturation.
• Denatured proteins are biologically inactive.
• Anything that disrupts bonding can denature a
  protein.

54
NUCLEIC ACIDS

• Nucleic acids are polymers of information, they
  are the building blocks of DNA and RNA.
• Nucleic acids are units of heredity. They store
  and transmit genetic information.
• The building blocks of nucleic acids are
  nucleotides each nucleotide contains a phosphate
  group, a pentose sugar, and a nitrogenous base
  (A,T,C,G,U).

55
NUCLEIC ACIDS consist of phosphate group,
pentose sugar, nitrogenous base
56
Types of Nucleic Acids

• Exist as 2 types DNA and RNA
• DNA -- double stranded (entire code)
• sugar is deoxyribose
• never leaves nucleus
• bases are A,T,C,G
• involved in replication and protein
  synthesis
• RNA -- single stranded (partial code)
• sugar is ribose
• mobile nucleus and cytoplasm
• bases are A,U,C,G
• involved in Protein Synthesis

57
Interactive review Macromolecules

• http//www.classzone.com/cz/books/bio_07/resources
  /htmls/interactive_review/bio_intrev.html

Complete this interactive review using your
virtual textbook at home. Concept maps are an
excellent way to organize your thoughts and
review material!
58
(No Transcript)
59
Bonds break and form during chemical reactions.

• Everything that happens in an organism its
  growth, its interaction with the environment, its
  reproduction, and even its movement is based on
  chemical reactions.
• A chemical reaction is a process that changes one
  set of chemicals into another set of chemicals
• Chemical reactions can occur slowly or very
  quickly.
• The elements that enter into a chemical reaction
  are known as reactants.
• The elements or compounds produced by a chemical
  reaction are known as products.
• Chemical reactions always involve the breaking of
  bonds in reactants and the formation of new bonds
  in products.
• Energy is released or absorbed whenever chemical
  bonds form or are broken.

60
Metabolic Processes

• Metabolism is the totality of an organisms
  chemical reactions (all processes that involve
  building materials or breaking down materials)
• Catabolic degradative processes, where complex
  molecules are broken down into simpler compounds
  and energy is released.
• Ex. Cellular respiration
• Anabolic consume energy to build complicated
  molecules from simpler ones.
• Ex. Photosynthesis
• These pathways intersect in such a way that the
  energy released from Catabolic processes can be
  used to drive Anabolic processes.
• This transfer of energy is called Energy Coupling

61
Energy Changes in Exergonic and Endergonic
Reactions
Exergonic Reaction Reaction proceeds with a net
RELEASE of free energythese reactions occur
spontaneously.
Endergonic Reaction Reaction proceeds with an
ABSORPTION of free energythese reactions are not
spontaneous.
62
WebQuest Prions Public Healthhttp//www.classz
one.com/cz/ot/bio_webquest/02/intro.jsp

• Prions are misfolded proteins that cause mad cow
  disease and, in humans, Creutzfeldt-Jakob
  disease. In this webquest, you will learn about
  prions and how they infect people and other
  animals. Determine if the drastic steps taken to
  prevent the spread of prions actually keeps
  people safe.

63
AKS Standards 8j - explain how enzymes function
as catalysts (GPS)
64
Activation Energy

• Chemists call the energy that is needed to get a
  reaction started the activation energy.
• Some chemical reactions that make life possible
  are too slow or have activation energies that are
  too high to make them practical for living
  tissue.
• These chemical reactions are made possible by
  catalysts.
• A catalyst is a substance that speeds up the rate
  of a chemical reaction
• Catalysts work by lowering the activation energy
  needed to make the reaction occur.

65
Enzymes allow chemical reactions to occur under
tightly controlled conditions.http//www.sumanasi
nc.com/webcontent/animations/content/enzymes/enzym
es.html

• Enzymes are proteins that act as biological
  catalysts.
• Cells use enzymes to speed up chemical reactions.
• Enzymes act by lowering the activation energies
  required to start these chemical reactions.
• Enzymes are very specific, generally catalyzing
  only one chemical reaction.
• Enzymes are not changed or used up during
  chemical reactions.
• Enzymes cannot cause chemical reactions these
  reactions would all occur naturally, just at a
  slower rate!

66
Chemical Reactions and Enzymes

• Activation energy- energy needed to get a
  reaction started
• Enzymes are proteins that act as biological
  catalysts (speed up a reaction) by lowering the
  activation energy required to start the reaction.

67
Enzymes in Action

• For a chemical reaction to take place, the
  reactants must collide with enough energy so that
  existing bonds will be broken and new bonds will
  be formed.
• Enzymes speed up chemical reactions by providing
  a site where reactants can be brought together to
  react.
• Such a site reduces the energy needed for the
  reaction by placing the reactants in a position
  favorable for the reaction to occur.
• The reactants of enzyme-catalyzed reactions are
  known as substrates.
• Enzymes can be affected by changes in pH, changes
  in temperature and can be turned on or off at
  critical stages in the life of a cell.

68
The Active Site of Enzymes

• The reactant an enzyme acts on is its substrate.
• Enzymes are substrate specific, and can
  distinguish its substrate from even closely
  related molecules!
• Each enzyme has an active site the catalytic
  center of the enzyme! This is the area where the
  enzyme attaches to or reacts with the substrate.

69
Chemical Reactions and Enzymes
70
Physical and Chemical Environments Affects Enzyme
Activity

• Because they are PROTEINS, the shape of an enzyme
  is very important in determining its function.
  Anything that changes the shape of an enzyme
  will interfere with its ability to react with its
  substrate.
• Temperature too high, denatures protein too
  low, freezes protein in such a way that it cannot
  alter its shape to react
• pH too high or too low, denatures protein
• Salinity ions of salt can compete with an
  enzymes bonds and denature the protein
• Cofactors inorganic nonprotein helper bound to
  active site must be present for some enzymes to
  function (zinc, iron, copper)
• Coenzymes organic nonprotein helper bound to
  active site again, must be present (vitamins)
• http//www.sumanasinc.com/webcontent/animations/co
  ntent/proteinstructure.html

71
Inhibitors

• Enzyme Inhibitors stop enzyme from working!
• 2 types competitive and noncompetitive
• Competitive blocks active site, mimics substrate
• Noncompetitive bind to another part of enzyme and
  change shape of enzyme so cant work on
  substrate
• http//bcs.whfreeman.com/thelifewire/content/chp06
  /0602001.html

72
Inhibition of Enzyme Activityhttp//bcs.whfreeman
.com/thelifewire/content/chp06/0602001.htm
Enzyme Inhibitors stop enzyme from working.
There are 2 types of enzyme inhibitors
competitive and noncompetitive.
Competitive inhibitors mimic the substrate and
competes for the active site. This effectively
blocks the enzyme from working.
Noncompetitive inhibitors bind to the enzyme at a
location away from the active site, but alters
the shape of the enzyme so that the active site
is no longer fully functional.
73
Critical Thinking Activities Inferring
Connecting Concepts

• Some organisms live in very hot or very acidic
  environments. Would their enzymes function in a
  humans cells? Why or why not?
• Organisms need to maintain homeostasis, or stable
  internal conditions. Why is homeostasis
  important for the function of enzymes?
• No, those enzymes function under different
  conditions than are found in humans.
• If homeostatic conditions, such as temperature or
  pH, are not maintained, then the hydrogen bonds
  that keep an enzyme in its correct shape will
  weaken or break and the enzymes structure will
  change this will affect its function.