Unit 2 Review

Key Point 2:

●DNA has the instructions to make proteins- these proteins give you
your traits!

Ex:

GENE FOR LACTASE RNA COPY OF GENE LACTASE ENZYME TRAIT (LACTASE PERSISTENCE)

If you
stretched the
DNA in one
cell all the
way out, it
would be
about 2m
long

Key Point 3:

●ALL living things have DNA
made of the same monomers,
called “nucleotides”- we call
this a universal genetic code!

Multiple Choice

What is shared by ALL living things?

• Mechanisms of digestion

• Motility

• Genetic material composed of DNA

• Chloroplasts

●DNA is a nucleic acid with
a double helix shape
(double= two strands,
helix=twisted).

●First proven with an image
taken by Rosalind Franklin

Key Point 4

Multiple Choice

This image first proved...

• DNA bases pair A-T, C-G

• DNA folds into a double helix

• DNA forms chromosomes

• DNA has bases

• DNA is made of repeating

monomers callednucleotides

• Nucleotides have:

– A phosphate group

– A sugar (deoxyribose)

– A base (A, C, T, G)

Key Point 5

P

Sugar

Base

Key Point 6:

4 Nitrogenous Bases:

– Adenine
– Thymine
– Cytosine
– Guanine

● A pairs with T
● C pairs with G

Multiple Choice

Write the complementary strand for ACGGTTCCA

• TGCCAAGGT

• ACGGTTCCA

• GTAACCTTG

• ACCTTGGCA

Key Point 7:

● Bases are connected byhydrogen bonds.

Key Point 7:

● Theorder/sequence of the bases/nucleotides determines the protein

made, and therefore your traits!

GENE FOR LACTASE RNA COPY OF GENE LACTASE ENZYME TRAIT (LACTASE PERSISTENCE)

Multiple Choice

What part of DNA determines traits (has the genetic code) with the information for a specific protein?

• Double-Helix shape

• The Phosphate and Sugar backbone

• The sequence (order) of nucleotides

• The hydrogen bonds connecting the strands

Key Point 1:

●

Proteins are made of amino
acids. These amino acids
interact with one another
and can fold into many
unique 3D shapes.

Multiple Choice

The monomer for a protein is a(n)...

• fatty acid

• nucleotide

• monosaccharide

• amino acid

Key Point 2:

●The structure (shape) of the molecule determines its function (job).
This is true forenzymes, which are specificto one type of molecule.

Example: the structure of an enzyme determines what it can react with.

Turn and talk to your partner:

Some scientists describe
enzymes with the phrase “lock
and key model”. What do you
think this phrase means?

M: Seated
V: Level 1-2
P: Talking to neighbor
T: 1 minute

Turn and Talk

The Parts of an Enzyme-Catalyzed Reaction

Multiple Choice

The enzyme catalase works on the substrate hydrogen peroxide. Why can catalase only work on hydrogen peroxide?

• The enzyme has an active site that is specific to hydrogen peroxide

• The enzyme has an active site that can fit many different substrates

• The enzyme is occupied by an inhibitor molecule

• The enzyme is denatured

Optimum Conditions

● Enzymes work best at a specific

optimum temperature and pH
(acidity).

● Optimum = Best.
● At lower temperatures, the

enzyme works more slowly

● If conditions become too extreme

(hot, high/low pH), the enzyme
will denature, or lose its shape

Inhibitors

● If the wrong molecules get into the

enzyme’s active site, they get in the way
of substrate- this is called inhibition

● This makes the enzyme unable to react

M: Seated
V: Level 0
P: Taking notes
T: 1 minute

Multiple Choice

Which of the following statements about inhibitors is true?

• Inhibitors help substrate to bond to the enzyme.

• Inhibitors block the active site of the enzyme.

• Inhibitors speed up enzyme reactions.

• Inhibitors denature enzymes.

Enzymes and Chain Reactions

● Many times,

multiple
enzymes will
work together to
turn a substrate
into a final
product

● The enzymes

work like an
assembly line

Enzymes and Chain Reactions

● So what

happens if one
of the enzymes
denatures?

How to Solve Denaturation Problems

CFS:
❏

Identify the denatured enzyme

❏

Cross the enzyme out on the
pathway

❏

Write an up arrow over the
substrate before the enzyme

❏

Write a down arrow over the
substrate after the enzyme

1.

Which substrate will increase if
enzyme 2 is denatured?

Multiple Choice

If enzyme 2 denatures, which substrate increases?

• The green triangle

• The purple rectangle

• The blue molecule

• The yellow square

Key Point 2:

●The structure (shape) of the molecule determines its function (job).

Example: the structure of an enzyme’s active site determines what substrate it can
react with.

Multiple Choice

If 2 proteins have different structures, they also must have...

• different functions

• different monomers

• different elements

• similar functions

Key Point 3:

●Each biomolecule can exist as
a single unit, or monomer, or a
long chain of units, called a
polymer.

Multiple Choice

Which of the following shows a monomer?

Key Point 1:

●

There are 4 biomolecules:
○Carbohydrates

○Proteins

○Lipids

○Nucleic Acids

Key Point 4: Carbohydrates

Carbohydrates are used for fast/short term
energy.

Monomer: monosaccharide

Function: fast/ short-term energy
_____________________________________

Bonus info:

Other names: “sugars”, “polysaccharides”

Examples: starch, glucose, fructose, lactose,
cellulose.

Found in: Bread, pasta, rice, fruit, vegetables

Key Point 5: Lipids

Lipids are used for long-term energy,
insulation, and in cell membranes.
Monomer: fatty acids and glycerol

Function: long-term energy, insulation,
cell membranes
________________________________
Bonus info:

Other names: “fats”

Examples: triglycerides, cholesterol

Found in: Butter, oil, animal fat

Multiple Choice

What is a shared function of lipids and carbohydrates?

• Catalyzing reactions

• Building muscle

• Storing genetic information

• Energy storage

Key Point 6: Proteins

Proteins are used to build muscles and other
structures, like hair, and to speed up chemical
reactions.

Monomer: amino acid (Memory trick: Tienes
proteina? A mi! No!)

Function: build muscles, structure, chemical
reactions (enzymes)
____________________________________
Bonus info:

Other names: “polypeptide”

Examples: muscle fiber, enzymes

Found in: Meat, fish, eggs, dairy, nuts, beans

Key Point 7: Nucleic Acids

Nucleic Acids are used to store genetic
information (instructions to make
proteins).
Monomer: nucleotide

Function: store genetic information
(instructions to make proteins)
_________________________________
Bonus info:

Other names: none

Examples: DNA, RNA

Found in: The cells of every single
living thing!