Transcript What are atoms and molecules?

Unit 1 Lesson 2 Chemistry of Life
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Unit 1 Lesson 2 Chemistry of Life
It’s Elementary
What are atoms and molecules?
• All cells (and all matter) are made up of atoms
and molecules.
• An element is a substance that cannot be broken
down into a simpler substance.
• The smallest unit of an element that maintains the
properties of that element is called an atom.
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Unit 1 Lesson 2 Chemistry of Life
What are atoms and molecules?
• What are the six main elements that make up the
human body?
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Unit 1 Lesson 2 Chemistry of Life
What are atoms and molecules?
• A molecule is a group of atoms held together by
chemical bonds.
• Some molecules are made up of only one type of
atom.
• Most molecules are made up of two or more types
of atoms.
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Unit 1 Lesson 2 Chemistry of Life
What are atoms and molecules?
• A compound is a substance made up of atoms of
two or more elements joined by chemical bonds.
• Most molecules found in cells are compounds.
• Compounds have different properties than the
elements that make them.
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What is a macromolecule?

Macro = large

There are 4 groups of large molecules that are found in
large quantities in our bodies.

They are:

Carbohydrates
Proteins
Lipids
and



Nucleic Acids
Macromolecules are polymers.

Poly- = many

-mer = unit
Polymers are long molecules built by linking repeating
building blocks or units in a chain
A Polymer
Here are some analogies to better understand what
polymers and monomers are….
EXAMPLE of
POLYMER
A TRAIN
A NECKLACE
MONOMER
?
?
If the train is the whole polymer, what would be the small groups
that make up the train? If the necklace is the polymer, what are
the monomers that make up the necklace?
Look at the label to the
left.
3 of the 4 macromolecules
can be found in foods.
Organisms use nutrients
for energy and as
building materials
(0 grams in this
product)
(13 grams in this product)
(9 grams in this product)
When studying these
biochemical molecules, we
are interested in finding
out…..

what they do for living things.

what they generally look like.

what their monomers are.

and how they may help the body gain energy to
sustain life.
Unit 1 Lesson 2 Chemistry of Life
What are some important types of
molecules in cells?
• A lipid is a fat molecule or a molecule that has
similar properties. Lipids have many jobs in cells,
such as storing energy.
• Your cells get lipids from foods such as olive oil,
butter, nuts and fish.
• They are made up of chains of triglycerides
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LIPIDS – What do they do
They are a great source of STORED ENERGY so we
have it in the future.
They INSULATE the body to maintain normal body
temperature and they CUSHION the internal organs for
protection.
They produce hormones for the body called STERIODS
They waterproof surfaces of animals,plants, and fruitsthese are waxes!
THINK: Waterproof, insulate, steriods, energy, cushion…
“WISE C”
Unit 1 Lesson 2 Chemistry of Life
What are phospholipids?
• What causes a cell membrane to have a doublelayer structure?
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Unit 1 Lesson 2 Chemistry of Life
What are some important types of
molecules in cells?
• A protein is a molecule made up of smaller
molecules called amino acids.
• Protein-rich foods are broken down into amino
acids, which make new proteins to build and
repair body structures.
• Proteins called enzymes help chemical processes
happen in cells.
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Unit 1 Lesson 2 Chemistry of Life
What are some important types of
molecules in cells?
• Carbohydrates are molecules that include
sugars, starches, and fiber.
• Cells use carbohydrates for energy and energy
storage.
• Simple carbohydrates are made of one or a few
sugars linked together. Complex carbohydrates
contain many sugar molecules linked together.
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Unit 1 Lesson 2 Chemistry of Life
What are some important types of
molecules in cells?
• Nucleic acids are molecules that carry
information in cells.
• Nucleotides are the smaller molecules that make
up nucleic acids.
• DNA is a nucleic acid that carries information that
cells need to make other molecules.
• You do not get energy from nucleic acids
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Energy that we gain by the
consumption of food is
measured in Calories.
If you drink a glass of skim milk, you
will get a gain of 90 Calories of
energy for your body.
Energy Gained From
Carbohydrates
Eating 1 gram of carbohydrate provides your
body with 4 Calories.
Energy Gained from Lipids
Eating 1 gram of fat provides your body with
9 Calories.
Notice if you eat 1 gram of fat, you are
gaining more than twice the amount of
Calories than from a gram of
carbohydrate or protein!
ENERGY
So…
MACROMOLECULES
Number of Calories it
provides
Carbohydrates
4
Proteins
4
Lipids
9
Nucleic Acids
0
BIG 4
TEST:
Are you smart? If you eat a sandwhich with 46 grams of carbs and 24
grams of protein and 10 grams of fat, how much energy will you gain?
Unit 1 Lesson 2 Chemistry of Life
Waterworks
What are phospholipids?
• A lipid that contains phosphorus is called a
phospholipid.
• The head of a phospholipid molecule is attracted
to water. The tail repels water.
• Much of a cell’s membrane is made of a doublelayer of phospholipids, which regulates molecules
entering and leaving the cell.
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Unit 1 Lesson 2 Chemistry of Life
Why is water important?
• Water moves through a cell membrane by a
process called osmosis.
• Water moves into and out of a cell, from areas of
higher concentration to areas of lower
concentration.
• Too little water in a cell causes it to shrink.
• Too much water in a cell causes it to burst.
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