Do Now Make a list of foods that you eat and categorize them How will you categorize? Why? What...
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Transcript of Do Now Make a list of foods that you eat and categorize them How will you categorize? Why? What...
Do Now Make a list of foods that you eat
and categorize them
How will you categorize? Why?
What is in each one?
Prefixes and Suffixes to know
carbo- =“coal”
di- = “two”
hydro- =“water”
mono- =“one”
poly- =“much”
-ase = “enzyme”
-hydrate = “water”
-ose =“sugar”
-philic = “loving”
-phobic =“fearing”
-saccharide = “sugar”
Organic Molecules organic molecules: carbon based molecules
Carbon can form bonds with one or more other carbon atoms, producing an endless variety of carbon skeletons
hydrocarbons: composed of only carbon and hydrogen Important as fuels
Methane (CH4) - natural gas Energy-storing fat molecules
Inorganic Molecules
inorganic molecules: non-carbon based Ex. Water, O2,
NH3
Functional Groups functional groups: group
of atoms within a molecules that interact in predictable ways with other molecules
Hydroxyl group Called alcohols Polar Soluble in water
Carbonyl group Ketones and aldehydes Polar Some sugars
Carboxyl group Carboxylic acids Polar and soluble Acidic In amino acids
Amino groups Amino acids Slightly polar basic
Monomers and Polymers
monomers: small molecular units form a larger similar combination of hundreds or millions of atoms
polymers: long chains of repeating monomers Branching chains or folding Every living cell has thousands
of different kinds Made from a collection of fewer
than 50 kinds of monomers
4 main categories Carbohydrates -- Proteins Lipids -- Nucleic
acids
Building and Breaking Polymers
dehydration reaction: each time a monomer is added to a chain, a water molecule is released
hydrolysis reaction: water is added to a polymer to break it down Molecules in food are
polymers and need to be broken apart to be available to your cells
Monomers break down to obtain energy to make new polymers
5.2 Carbohydrates carbohydrate:
organic compound made up of sugar molecules
Sugars contain carbon, hydrogen and oxygen Ratio 1C:2H:1O Glucose= C6H12O6
Monosaccharides monosaccharide:
simple sugar that contains just one sugar unit Glucose, fructose
glucose: exists in straight-chain and ring-shaped forms Main fuel supply for
cellular work Unused molecules
are incorporated into larger carbs or to make fat
Disaccharides disaccharide:
“double sugar”; two monosaccharides combined by dehydration reaction
sucrose: most common; made of glucose and fructose Major carb in plant
sap and nourishes plants
Table sugar processed from sugar cane stems
Polysaccharides polysaccharide: long
polymer chains made up of simple sugar molecules Complex carbohydrates
glycogen: polysacch found in animals that act as a storage for excess sugar Chain of many glucose
monomers, but arte more highly branched than a starch monomer
In humans, most glycogen is stored as granules in liver and muscle cells and break down when the body needs energy
Plant Polysaccharides starch: found in plant
cells and consists entirely of glucose monomers Chains branch and coil up
in loops “sugar stockpile” =stored
energy
cellulose: serves at building materials; protect cells and stiffens plant Many glucose monomers Multiple chains are linked
by hydrogen bonds to form cable-like fibers in the tough plant cell walls
Does not dissolve in water
How to test for the presence of
carbohydrates in food Glucose:
glucose strip (easy) Benedict’s test: add Benedict’s
solution, place tube in boiling water for 5 minutes. Look for color change to red/brown
Starch Drop iodine on the product or
solution Changes to a purpleish black if
starch is present
Do Now Complete the Carbohydrates section of the chart
5.3 Lipids lipids: class of
compounds that is hydrophobic (water-fearing) Act as a boundary that
surrounds and contains the aqueous contents of your cells
Others circulate as chemical signals
Some are fats which store energy
Fats fats(triglyceride): a 3-carbon backbone(glycerol) attached
to 3 fatty acids(long hydrocarbon chains) Solid or liquid Fatty tissues cushion organs and provide body with insulation
saturated fats: all fatty acid chains contain the maximum possible number of hydrogen atoms All single bonds Solid at room temp Animal fats
unsaturated: less than max. number of H atoms in one ormore fatty acid chains Some double bonded Liquid at room temp. Most plant and fish oils
Steroids steroids: carbon
skeleton forms 4 fused rings Different functional
groups attached to rings
Different than fats in structure and function, but still hydrophobic
Cholesterol
Sex hormones
Cortisol
Vitamin D
Cholesterol cholesterol: essential
molecule found in cell membranes Starting point from
which your body produces other steroids
makes the lipid bilayer less deformable and decreases its permeability
Links to cardiovascular disease
LDL = low density lipoprotein “bad”
HDL = high density “good”
Triglycerides(fat)
Lipid Tests Paper Bag Test
Place the food on a paper bag Positive: leave a “stain” on the bag
Emulsion (Ethanol) Test Add the food sample to 2 cm3 of
ethanol, shake well. Allow to settle in a test tube rack for
2 minutes for food to dissolve in ethanol.
Empty any clear liquid into a test tube containing 2 cm3 of distilled H2O.
A MILKY-WHITE EMULSION is a positive result: lipid is present.
If the mixture remains clear, there are no fats present in the sample
Do Now
1. List 3 functions of proteins.
2. What foods are proteins found in?
3. What is the purpose of an enzyme?
5.4 Proteins protein: a polymer
constructed from a set of just 20 kinds of monomers called amino acids. responsible for
almost all of an organism’s functioning
Enzymatic, transport, structure, storage hormonal, receptor, contractile, defensive
Protein Structure amino acid: monomer that consists of a central carbon atom
bonded to four partners (carbon forms 4 bonds) three of the central carbon’s partners are the same in all amino
acids the “side group” or the “R-group” is responsible for the particular
chemical properties of each AA.
Polypeptide: chain of amino acids
that make up a protein dehydration reaction between amino group of one and a carboxyl of the next proteins = one or more polypeptide chains most chains are at least 100 AA
Shape polypeptides are
precisely twisted, folded, and coiled into a unique shape for each protein
influenced by the surrounding environment which is usually aqueous
hydrophilic and phobic to different sides
Denaturation Denaturation:
unfavorable change in pH, temperature, or other quality of the environment that causes the protein to unravel and lose shape (ex. frying an egg;
albumin is egg white which turns from clear to white)
Protein Test Biurets
To a test tube, add 40 drops of liquid to be tested.
If testing more than one liquid, label each test tube with a marker.
Add 3 drops of Biuret reagent solution to each test tube. Shake gently to mix.
Note any color change. Proteins will turn solution pink or purple.
Do Now What are enzymes made of?
What is the purpose of them?
5.5 Enzymes enzymes: specialized
proteins in organisms that exist as catalysts they provide a way for
chemical reactions to occur at normal temperature
does not supply activation energy, but it lowers the energy requirement barrier
each enzyme is specific to one reaction
Always recycled
pH and temp can affect function
Catalysts Catalysts:
compounds that speed up chemical reactions
activation energy: activates the reactants and triggers a chemical reaction “start-up” energy heat can provide
activation energy, but may cause other reactions
How Enzymes Work the shape of the enzyme
fits the shape of only particular reactant molecules
substrate - a specific reactant acted upon by an enzyme
active site - the substrate fits into a particular region of the enzyme can change shape slightly
to fit snugly will accept two substrates
into adjacent sites
Nucleic Acids
DNA: dexoyribose nucleic acid
RNA: ribose nucleic acid