Review Question
One category of organic compounds contains
molecules composed of long hydrocarbon
chains. The hydrocarbon chains may be
saturated or unsaturated. Which of the following
categories of organic compounds contains these
molecules?
A carbohydrates
B lipids
C nucleic acids
D proteins
Proteins
(Polypeptides)
Objective:
B2 - Compare the structures & functions of
carbohydrates, lipids, proteins, & nucleic acids &
their organization into long complex molecules
Consist of:
 carbon, hydrogen,
oxygen, and NITROGEN
(monomers)
Building Blocks of Proteins
 Amino Acids
 There are 20 of them
 Held together by peptide
bonds
 Proteins range in size
from 10 amino acids to
34,350 amino acids!
Amino Acid
monomer
Protein polymer
Protein Functions:
- Control rate of reactions
- Regulate cell processes
- Form bones & muscles
- Part of cell transport
- Help fight disease
Examples of Proteins
 Structural (collagen, keratin)
 Hormones (insulin)
 Defensive (antibodies)
 Transport (hemoglobin)
 Receptor (part of cell membrane)
 Enzymes
Etymology
Peptide: (Gk. PEPTEIN, to digest)
Polypeptide: poly- (many) + -peptide
(to digest)
Monomer: mono- (one) + -mer (part)
Polymer: poly- (many) + -mer (part)
What do enzymes
have to do with
soft-drinks?
Enzymes
Objectives
B4 - Identify & investigate the role of enzymes
and summarize the importance of enzymes in
living systems
Enzyme Characteristics



proteins that act
as biological
catalysts (speed up)
speed up
(or catalyze)
chemical
reactions
lower activation
energies
Activation
energy
(continued)



reversible
are used over and over (reusable)
(are not changed by the reaction)
most work best at normal pH & body temperature
EnzymeSubstrate
Complex
Substrate
Active
Site
Enzyme
Product
Enzyme
(unchanged)
S
Enzymes

If homeostasis is not
maintained, denaturing can
occur
Enzymes
Specific – lock & key hypothesis
 Usually end in “-ase”

ATP synthase synthesizes ATP
 Lactase breaks down lactose
 Sucrase breaks down sucrose
 Pepsin breaks down protein (exception)


A person that is lactose intolerant
lacks the enzyme lactase rendering
him unable to digest lactose in milk
Lock & Key Model
Enzyme-Substrate Complex

Substrate - chemical substances acted upon


such as Food & Waste
Active Site - region of an enzyme where the
substrate binds prior to the reaction

on the enzyme
Practice Question
Use the diagram of the enzyme to
determine which substrate below would be
broken down by this particular enzyme.
a.substrate Q
b.substrate R
c. substrate S
d.substrate T
Practice Question
Which is the best way to describe the fit
between an enzyme and its substrate?
A The fit between them varies with the cell.
B The enzyme fits tightly with the substrate.
C The enzyme loosely fits inside the substrate.
D The substrate loosely fits inside the enzyme.
Practice Question
To
what macromolecule
do enzymes belong?
Protein
Practice Question
Which organic molecule is part of an
enzyme?
A fatty acid
B nucleotide
C amino acid
D monosaccharide
Starch
Amylase & Glucoamylase
Glucose
isomerase
Now…for the soda…
If an enzyme is breaking down a
carbohydrate, what would the
products be after the reaction?
Simple sugars /
Monosaccharides