Animal Physiology 1

Front 1

What is Chemistry?

Back 1

Chemistry = study of the composition of matter and the changes that matter undergoes

Front 2

Matter

Back 2

anything that occupies space and has mass.

Front 3

Mass

Back 3

Mass = a given quantity of matter regardless of the weight. The mass of an object would be the same on earth as it would on the moon which has much less gravity. The term, mass, should always be used when referring to “weight” in science. Weight is related to the pull of gravity on an object

Front 4

The physical states of matter

Back 4

Solid - ice
Liquid - water
Gas - steam

Front 5

What is a solid?

Back 5

definite volume
fixed shape
Low energy
Highest density
Molecules vibrate or wiggle but do not move to new positions in the solid.
In an ice cube, water molecules, H2O, move slightly (mainly vibrate) but do not change their relative positions.

Front 6

What is a liquid?

Back 6

a definite volume
conform to whatever container holds it
The water molecules in a glass of water can go anywhere in the liquid and actually have a fairly high velocity.
They constantly bounce into each other
They stick together
Migrate from one place to another
Relatively slow movement
Moderate energy
Moderate density

Front 7

What is a gas?

Back 7

Has neither a definite volume or shape
will occupy the entire container that holds it
When liquid water is boiled it becomes a gas
very high rate of speed
never stand still
Highest energy of all the states
Lowest density

Front 8

What do you have to do to change the physical state of matter?

Back 8

Physical changes of state require the input of energy in the form of heat

Front 9

Changes of states of matter

Back 9

 Solid to liquid
 Melting
 Solid directly to gas
 Sublimation
 Gas to liquid
 Condensation
Liquid to solid
Solidification
freezing

Front 10

What is a chemical change in matter?

Back 10

Chemical changes occur when an element or molecule reacts with another element or molecule to form completely different compounds

Front 11

What is an element?

Back 11

Pure substance that cannot be broken down into simpler substances by ordinary chemical changes
Is made up of atoms
Currently 109 elements have been identified
Some elements exist in the pure elemental form as solids, liquids or gases depending on the temperature.
Examples: gold (solid), oxygen (gas), mercury (liquid)
Many elements cannot exist without being combined with other atoms in the form of compounds.
This is called volatility
Examples: phosphorus, sodium

Front 12

What is a compound?

Back 12

a pure substance made up of two or more atoms in a fixed composition and combination
Examples: water (H2O), salt (NaCl), table sugar (C6H12O60

Front 13

What is an atom?

Back 13

The Greek philosopher Democritus (460-370 BC) first proposed that if a pure substance was divided
into smaller and smaller pieces, the result would be a small particle that could not be divided any further.

Dalton said:
compounds are formed by a combination of two or more atoms in definite arrangements in a ratio of small whole numbers
atoms are not created, destroyed or converted into other kinds of atoms during chemical reactions but are rearranged into new compounds.

Front 14

What is a nucleus?

Back 14

the center of an atom
protons
neutrons
accounts for nearly all the mass of an atom
Both protons and neutrons have masses equal to one atomic mass unit (amu or Dalton).
One atomic mass unit is a mass ratio based on the element carbon.
An amu is defined as the mass of a Carbon atom divided by twelve (12)
It is not the mass of a proton or neutron in grams

Front 15

What is a Proton?

Back 15

Subatomic particle which has a positive charge
the number of protons in a nucleus determines the identity of the atom (element)
This number is called the atomic number.

Front 16

What is a neutron?

Back 16

 A subatomic particle which has no charge.
 can be considered to be a proton and an electron held together by another subatomic particle called a gluon.

Front 17

 What are Isotopes?

Back 17

 Atoms of the same element that have different numbers of neutrons in the nucleus.
 Remember that it is only the number of protons that determines the identity of an element.

Front 18

 What is an Electron?

Back 18

Subatomic particles which have a negative charge and virtually no mass.
The mass of a single electron has been determined to be 9.11 x 10-28 gram
0.000000000000000000000000000911g

Front 19

 The structure of an atom:

Back 19

 Most of the mass of atom
 Dense, positively charged nucleus
 Has protons which are positively charged and neutrons which have no charge at all.

Front 20

 Most of the volume of an atom

Back 20

 is in an empty space around the nucleus.
 Negatively charged cloud of electrons
 The electrons are attracted to the nucleus by electrostatic attractions
 the velocity of the electrons prevents the electrons from collapsing in on the nucleus.
 This empty space is called a “potential” or orbital

Front 21

 Modern atomic theory

Back 21

 electrons surround the nucleus in orbitals and balance out the positive charges of the protons

 Orbitals

Front 22

 Orbitals:

Back 22

 The first energy level can hold up to two electrons in an orbital called the 1s orbital.
 The first energy level has the lowest energy and is closest to the nucleus.
 The shape of the 1s orbital is spherical.
 When this energy level or shell is filled, there is a considerable jump in energy required to go to the next energy level.
 Any element that has a filled shell will tend to be very stable because of this jump in the energy level.
 We call these particular elements inert (or noble) gases.

Front 23

 The second energy level can hold up to two (2) electrons in each of four (4) orbitals.

Back 23

 2s
 2px
 2py
 2pz
 The shape of the 2s orbital is spherical and the shapes of the 2p orbitals look a bit like dumbbells.
 Any element that has a second energy level also has a first energy level (1s orbital)
 So, an orbital map is able to be drawn depending on how many electrons an element has!
 There is one p orbital on each of the three Cartesian coordinates.

Front 24

 An atom of an element has the same number of protons and electrons.

Back 24

 Protons are never gained or lost in chemical reactions
 The number of electrons in the outer energy level can be changed.

Front 25

 Ions

Back 25

 When the number of electrons in the outer energy level changes, a charge imbalance will occur and this charged atom is called an ion.
 The atom either loses or gains electrons resulting in a atom with a positive or negative charge
 Cations - positively charged ions (has given up an electron)
 Anions – negatively charged ions (has accepted an extra electron)

Front 26

 What is a cation?

Back 26

 An ion that forms by loss of an electron resulting in a a positive charge
 Example:
 hydrogen atom
 single proton with a positive charge.
 In the 1s orbital there is a single electron with a negative charge.
 These balance out for an overall net charge of zero.
 remove the electron by a chemical reaction
 there would be no negative charge
 there would still be a positive charge
 So, an overall net charge of plus one.
 This cation for hydrogen is called a proton (H+1)...pretty original name, don't you think?

Front 27

 What is a anion?

Back 27

 An ion that gains electrons resulting in a negative charge
 Example: let's again look at the hydrogen atom.
 In the nucleus there is a single proton with a positive charge.
 In the 1s orbital there is a single electron with a negative charge.
 These balance out for an overall net charge of zero.
 If we add an electron by a chemical reaction
 there would be 2 negative charges but still only 1 positive charge
 overall net charge of minus one.
 This anion for hydrogen is called a hydride ion. (H-1)

Front 28

 Another word for ions

Back 28

is electrolyte
 Electrolytes have the ability to conduct electricity when dissolved in water or in a molten (liquid) state

Front 29

 What is the shape of the s orbital

Back 29

The shape of the s orbital is spherical.

Front 30

 What is the shape of the p orbital?

Back 30

The shape of the p orbital look a bit like dumbbells.

Front 31

Hydrogen (H)

Back 31

 Name: Hydrogen
Symbol: H
Atomic Number: 1
Atomic Mass: 1.00794 amu
Number of Protons/Electrons: 1
Number of Neutrons: 0

 Number of Energy Levels: 1
 First Energy Level: 1 (hmmm...doesn’t this level prefer 2 electrons?)

Front 32

Carbon (C)

Back 32

 Name: Carbon
Symbol: C
Atomic Number: 6
Atomic Mass: 12.0107 amu
Number of Protons/Electrons: 6
Number of Neutrons: 6

 Number of Energy Levels: 2
 First Energy Level: 2
Second Energy Level: 4 (hmmm…wouldn’t this level prefer 8 electrons?)

Front 33

Oxygen (O)

Back 33

 Name: Oxygen
Symbol: O
Atomic Number: 8
Atomic Mass: 15.9994 amu
Number of Protons/Electrons: 8
Number of Neutrons: 8


 Number of Energy Levels: 2
 First Energy Level: 2
Second Energy Level: 6 (hmmm…doesn’t this level prefer 8 electrons?)

Front 34

Nitrogen (N)

Back 34

 Name: Nitrogen
Symbol: N
Atomic Number: 7
Atomic Mass: 14.00674 amu
Number of Protons/Electrons: 7
Number of Neutrons: 7
 Number of Energy Levels: 2
 First Energy Level: 2
Second Energy Level: 5 (hmmm

Front 35

Chloride (Cl)

Back 35

 Name: Chlorine
Symbol: Cl
Atomic Number: 17
Atomic Mass: 35.4527 amu
Number of Protons/Electrons: 17
Number of Neutrons: 18

 Number of Energy Levels: 3
 First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 7 (hmmm…)

Front 36

Sodium (Na)

Back 36

 Name: Sodium
Symbol: Na
Atomic Number: 11
Atomic Mass: 22.98977 amu
Number of Protons/Electrons: 11
Number of Neutrons: 12


 Number of Energy Levels: 3
 First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 1 (hmmm)

Front 37

Potassium (K)

Back 37

 Name: Potassium
Symbol: K
Atomic Number: 19
Atomic Mass: 39.0983 amu
Number of Protons/Electrons: 19
Number of Neutrons: 20

 Number of Energy Levels: 4
 First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 8
Fourth Energy Level: 1
 Do you say hmmm?

Front 38

 What is an element?

Back 38

 Matter composed of a single kind of atom
 Elements cannot be reduced to simpler substances by normal chemical means
 Example: Gold
 you can slice & slice a chunk of gold until there is only one tiny particle that is left when you can’t chop away anymore is still gold
 All of the atoms in an element have the same number of protons
 Elements are the basic building blocks of matter and are represented in the periodic table

Front 39

 What is a compound?

Back 39

 Substance made up of two or more elements in a specific ratio.
 Example: Water (H20)
 a compound made up of two elements combined in a very specific way
 hydrogen (H)
 oxygen (O)
 Ratio: 2 hydrogen atoms to 1 oxygen
 A lot of compounds contain hydrogen and oxygen, but only one has the special 2 to 1 ratio we call water.
 Compounds are pure (nothing else but the elements in the compound)
 macroscopically homogeneous (cannot be separated by physical means)
 have properties unlike those of its constituent elements.

Front 40

 What is a molecule?

Back 40

 A compound that is covalently bonded.
 Note: it is technically wrong to call salt (NaCl) a molecule as it has ionic (not covalent) bonds.

Front 41

 What is chemical bond?

Back 41

 Elements gain, lose, or share valence electrons in order to fill their valance energy level and become “satisfied” (like a noble gas)
 The valence electrons are those in the outermost energy level
 bonds usually involve filling the outermost s and p orbitals

Front 42

 What is a covalent bond?

Back 42

 A chemical bond formed by the sharing of one or more electrons (especially pairs of electrons) between atoms
 Covalent bonds occur between two non-metals and tend to be non-electrolytes

Front 43

 What is an ionic bond?

Back 43

 A chemical bond that holds cations and anions together
 a bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
 Ionic bonds come from the transfer of electrons from a metal to a nonmetal
 Compounds that have ionic bonds are called salts
 Example: sodium chloride (salt)
 tend to be electrolytes

Front 44

 What is an electrolyte?

Back 44

 A substance that conducts electricity in the molten state or when dissolved in water.
 Non-electrolytes don’t conduct electricity in these states
 Try placing an electrode in a simple sugar solution (1:1 ratio of sugar to water) vs. a salt solution and read it on an ammeter. The simple sugar solution will not register, the salt solution will!

Front 45

 What is a Carbohydrate?

Back 45

 “Carbohydrates are hydrated carbon or "carbon plus water“
 Cn(H2O) n
 Carbohydrate classification
 Monosaccharides
 Oligosaccharides
 Polysaccharides
 The most common monosaccharides
 glucose – a hexose sugar
 Fructose – a pentose sugar
 Common oligosaccharides
 sucrose (a disaccharide)
 One glucose and one fructose bonded together with an -glycosidic bond
 Hydrolysis of sucrose (a chemical reaction) yields glucose and fructose.
 glycogen (a disaccharide)
 consisting of 2 glucose molecules
 Stored in the liver of animals in chains
 Soluble carbohydrates are composed mainly of mono- and disaccharides
 can be used immediately for energy.
 Polysaccharides
 Starches
 found in plants
 consists of amylose (about 25% of all starches) and amylopectin (about 75% of all starches).

Front 46

 What is a Lipid?

Back 46

 Fats!
 Fats are called triglycerides because three fatty acids are joined to the glycerol (an alcohol) by ester linkages.
 An alcohol may be identified by an –OH group on a Carbon chain!

Front 47

 Lipids = Fats

Back 47

 Fatty acids
 building blocks of fat
 saturated no double bonds in the chain
 unsaturated double bonds are present in the chain
 Examples:
 Oleic acid contains one double bond
 mono-unsaturated fatty acid
 Linoleic acid contains two double bonds
 Polyunsaturated fatty acid
 Linolenic acid contains three double bonds
 Polyunsaturated fatty acid
 Stearic acid has no double bonds
 Saturated fatty acid. See previous slide

Front 48

 Triglycerides are three fatty acids attached to the glycerol backbone

Back 48

 fats are triglycerides that are solid at room temperature
 Have more single bonds (saturated fatty acids)
 Example: Lard, Crisco, butter

Front 49

 oils are triglycerides that are liquid at room temperature

Back 49

 Have more double bonds (unsaturated fatty acids)
 Double bonds cause “kinks” in the fatty acid chain so they don’t pack together as tightly as the saturated fatty acids
 Example: vegetable oils

Front 50

 Essential Fatty Acids (EFA)

Back 50

 required by the body and cannot be synthesized by the animal
 must be in the diet

Front 51

 Three EFA are required in small animals:

Back 51

 Linoleic acid – dog and cat
 Linolenic acid – dog only
 Arachidonic acid – cat only
 When fats are metabolized to carbon dioxide and water, they provide 9.3 kilocalories per gram of fat.
 This high yield of calories per gram of fat is the reason that high fat diets may lead to obesity.
 The same intake of carbohydrates (in grams) provides only one third of the calories per gram.
 we cannot eliminate all fat from our diet!!!
 fat provides building blocks for
 cell membranes
 nerve sheaths
 Hormones
 They are also involved in many other biochemical functions.

Front 52

 What are Amino Acids?

Back 52

 Building blocks for Proteins
 there are approximately twenty (20) naturally occurring amino acids
 Amino Acids
 Essential Amino Acids
 amino acids that cannot be synthesized in the body.
 These must be in the diet
 Examples:
 Cats must receive taurine in their diet
 Dogs may require Carnitine in certain breeds
 Excess protein will be burned for energy and can provide 4 kcal/g

 Ex: the amino acid Alanine (Ala-)
 grey - carbon
 white - hydrogen
 blue - nitrogen
 red - oxygen

Front 53

 What are Peptides?

Back 53

 Two individual amino acids linked to form a larger molecule, with the loss of a water molecule as a by-product of the reaction.
 The newly created C-N bond between the two separate amino acids is called a peptide bond.
 Two molecules linked by a peptide bond become what is called a dipeptide.
 A chain of molecules linked by peptide bonds is called a polypeptide

Front 54

 What are Proteins?

Back 54

 A protein is made up of one or more polypeptide chains, each of which consists of amino acids
 Instead of writing out complex formulae, sequences of amino acids are commonly written using the previously mentioned three- or one-letter codes
 Example:
 3 letter: ala-gly-val-leu-phe
 1 letter: AGVLF
 Note: anytime you see a compound name ending with -in or –ine…you can be sure it is an amino acid or protein.
 Dietary proteins are metabolized into smaller polypeptides in the stomach by an enzyme called pepsin.
 These polypeptides are metabolized to individual amino acids in the small intestine.
 The amino acids are absorbed through the intestinal wall into the bloodstream.