BiomoleculesWhat molecules keep us alive, and how

do they do so?

Biomolecules

All living organisms require several compounds to continue to live.

We call these compounds biomolecules. All of these biomolecules are organic, which means that they contain carbon.› Carbon has four valence electrons, which

means this element forms strong covalent bonds with many other elements.

Biomolecules

All of our biomolecules are classified into four groups:› Carbohydrates› Lipids› Proteins› Nucleic Acids

Each of these classes have different structures and functions.

Biomolecules

Also, our biomolecules are formed by joining many small units together to form a long chain.

This process is called synthesis. Often, a water molecule is removed in the process.› When this happens, we

call it dehydration synthesis.

Biomolecules

The smallest functioning unit of a biomolecule is a monomer.› “Mono-” means ONE.

Put two monomers together, and you get a dimer.› Di-” means TWO.

Once several monomers are put together, we get a polymer.› “Poly-” means MANY.

Carbohydrates

Carbohydrates (carbs) are biomolecules used for energy and structural support.

Breaking carbs down provides us with energy.

Carbohydrates

Carbohydrates are made up of carbon, hydrogen and oxygen.

The ratio of these elements is roughly 1carbon: 2 hydrogen :1 oxygen.

Monomer: Monosaccharide

Dimer: Disaccharide

Polymer: Polysaccharide

Carbohydrates

Carbs are primarily used to provide us with energy.

All monosaccharides and dissachardies end in “-ose”.

Glucose is used as a common energy source for most living organisms.

Carbohydrates

There are many other types of carbs in nature:› Fructose (fruit

sugar)› Lactose (milk

sugar)› Sucrose (table

sugar)› Ribose/Deoxyribose

(important for DNA and RNA)

Carbohydrates

Carbs can be bonded to each other through dehydration synthesis.› Remember, that’s

when water is lost as two smaller molecules bond to form a larger molecule.

Carbohydrates

Carbohydrates

When we have excess carbs, we store them as starches, which are polysaccharides.

Starches are long chains of carbs.

Plants also use cellulose (another polysaccharide) for structural support.

Carbohydrates

Indicators are chemicals that detect the presence of a certain compound.

Benedict’s solution reacts with MOST mono- and disaccharides.› Sucrose is a

notable exception!

Carbohydrates

If a detectable carbohydrate is present, then the indicator changes color, based on how many carbs are present.› Green → Yellow →

Orange → Red This is useful for

diagnosing diabetes.

Carbohydrates

Iodine is used to detect starch, since it reacts readily with starch.› This reaction

produces a purple-black coloration.

Exit Ticket

1. A ________ is made up of several smaller units, or monomers.

2. What are the two primary uses of carbohydrates?

3. Carbs can be identified because they end with the suffix ______.

4. ________ is the common energy source form almost all life on Earth.

5. Excess carbs are stored in our bodies as ________.

Bell Ringer

Use the diagram to solve the problems:

1. Lactose is an example of what type of carb?

2. What process joined these two carbs together?

Lipids

Lipids are used for four crucial purposes:› Storing energy› Waterproof barriers› Chemical

messengers› Insulation

Lipids

Lipids are made up of carbon, hydrogen and oxygen.

The ratio of these elements is roughly 1carbon: 2 hydrogen. Oxygen is present only in trace amounts.

Most common lipids are composed of two different functional groups:

Glycerol, an alcohol with three oxygen groups.

Fatty acids, which are long hydrocarbon chains.

Lipids

ALL lipids repel water, due to how hydrophobic they are. This means that they do not bond to water molecules.

Lipids

Lipids are grouped by the number of double bonds found in the hydrocarbon chain.

Saturated fats have the maximum number of hydrogen atoms possible, and as such, they have no double bonds.› They tend to be solid

at room temperature.

Lipids

Unsaturated fats have double bonds. They do NOT have the maximum possible number of hydrogen atoms.› They tend to be

liquid at room temperature.

Monounsaturated fats have only ONE double bond.

Polyunsaturated fats have MORE THAN ONE double bond in the hydrocarbon chain.

Lip

ids

Monounsa

tura

ted

Poly

unsa

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Lipids

It’s important to note that fats are a specific type of lipid.

Chemically, all fats are triglycerides – they have three fatty acids bonded to one glycerol molecule.

Lipids

Steroids are lipids with four rings bonded together.

Steroids are vital as hormones, which are chemical signals used in the body.

Lipids

Oily and fatty foods tend to leave stains upon contact.› This is why we can

use brown paper to detect fats.

We can also use ethanol, which dissolves lipids.

The dissolved fats are then diluted with water. Since water and lipids don’t mix, the lipids come out of solution.› This creates an

emulsion – a milky, cloudy liquid.

Exit Ticket

1. Show the ratio of carbon : hydrogen : oxygen in lipids:

2. All lipids are [hydrophilic, hydrophobic].

3. True or false: Saturated fats have no double bonds, and the maximum number of hydrogen atoms.

4. Monounsaturated fats have __________ double bond(s).

5. _________ serve as hormones.

Protein

Proteins serve many vital functions in your body:› Structural support› Speeding up

chemical reactions› Transport of

molecules› Fighting infection› …and many more!

Protein

All proteins contain carbon, hydrogen, oxygen and nitrogen.

In addition, sulfur may be present as well.

Monomer: Amino acid

Polymer: Protein or polypeptide› A peptide is a chain

of amino acids, so a polypeptide is several chains put together.

Protein

ALL amino acids contain an amino or N-group. It contains nitrogen (N).

ALL amino acids also contain a carboxyl or C-group. It contains carbon (C).

Protein

However, amino acids also have a variable group or R-group. This differs from one amino acid to the next.› There are 20

standard amino acids, and thus 20 possible R-groups.

Protein

Amino acids are bound together through dehydration synthesis.› The C-group of one

amino acid binds to the N-group of another.

› We call these bonds peptide bonds.

Protein

Proteins have four phases of production:› Primary: Amino acids are bound together.› Secondary: Individual amino acids are

bent and molded as needed.› Tertiary: The entire chain of amino acids

is bent and molded as needed, forming a sub-unit.

› Quaternary: Multiple completed sub-units are fitted together to make a complete protein.

Protein

Protein can also function as hormones.› However, protein

hormones tend to have difficulty passing the cell membrane.

As such, many protein hormones have to fit a cellular receptor before they can affect the cell.

Protein

The Biuret test is used to detect protein.

First, protein is dissolved in water. Then, a strong base is added to the solution.

Finally,

Exit Ticket

1. What biomolecule is being built?

2. Amino acids are bonded together in the _________ step of production.

3. Amino acids are held together with a _________ bond.

Hydrolysis

Hydrolysis is the reverse process of dehydration synthesis.

In dehydration synthesis, water is lost to create a bigger molecule.

In hydrolysis, water is ADDED, and a bigger molecule is broken down into smaller pieces.› Hydrolysis = hydro and lysis. Hydro means

water, and lysis means to break down.

Hydrolysis

Nucleic Acids

Nucleic acids are biomolecules that contain the blueprints for making proteins. Nucleic acids also transmit genetic info to the next generation.

Includes:› DNA› RNA

Nucleic Acids

Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.

Remember the acronym: CHONP!

Monomer: Nucleotides

Polymer: Nucleic Acid

Nucleic Acids

A nucleotide is made up of three parts:› 5-carbon sugar› Phosphate group› Nitrogenous base

A nucleoside, however, is the sugar and the base WITHOUT the phosphate.

Nucleic Acids

The 5-carbon sugar is deoxyribose, in the case of DNA.

However, it is ribose in the case of RNA.› This is how those

molecules got their name!

Nucleic Acids

The fifth carbon of the sugar is bonded to a phosphate group. Thus, we say that this is the 5’ end.

The third carbon of the sugar is bonded to an OH group. This is called is the 3’ end.

Nucleic Acids

As stated earlier, nucleic acids are the blueprints for proteins. Proteins are made from these templates.

Also, DNA can be passed on from parent to child. This allows SOME characteristics to be passed down to offspring. These traits are considered hereditary.

RNA can NOT be passed down to offspring, however!

Exit Ticket

1. The monomer of a nucleic acid is a ____________.

2. All nucleotides contain which three components?

3. DNA carries information down from generation to generation. This information is _____________.

4. DNA and RNA contain which elements?