Macromolecules Part 2PROTEINS, NUCLEIC ACIDS, AND WRAP UP

Bonding in macromolecules Monomers becoming polymers are synthesis reactions. (something bigger is being made, or synthesized) These reactions are often called dehydration synthesis, because at the site of the bond, one water molecule is released. This can also be called condensation synthesis.

When polymers are broken down, energy is released from the breaking of bonds. These are called decomposition reactions.

NOW ONTO PROTEINS

They are the major structural molecules in living things for growth and repair : muscles, ligaments, tendons, bones, hair, skin, nails…IN FACT ALL CELL MEMBRANES have protein in them

They make up antibodies in the immune system

They make up enzymes for helping chemical reactions

They makeup non-steroid hormones

THINK: Proteins= membranes, enzymes, antibodies, non-steriod hormones, structural molecules, “MEANS”

MORE ON PROTEINS…

The following slides give you a little more

in depth info on things that are made

of proteins…

Muscles, ligaments, tendons, and bones

Without these particular structural proteins, we would look more like this….

Well, maybe not exactly…

Hair, Skin, and Nails

Microscope View ofSkin and Nails

This is skin This is a nail

PROTEINS

•In plant foods- in the cell membranes and seeds

•In animal products- in the cell membranes and in the muscles of living things- cows, chicken, fish…

Proteins

Proteins

Aside from the protein found in animal sources…protein can also be found in fruits, vegetables, grains, and nuts. (it just does not have as many amino acids)

PROTEINS

Proteins are made of long chains (polymers) made of monomers. All proteins are

made of the monomer…

The shapes of proteins are like a balled up piece of stringAmino

Acid chain

All wound up

PROTEINS

Each protein is made up of…

THINK: “CHONS”

ProteinsMonomers-Amino acidsAmino acid group + Acid group + Variable groupFunctional group = group of atoms that give a molecule some properties

Polymers: polypeptide chainsBonds called peptide bonds

Protein structure Proteins have four levels of organization/structure:

Primary is just the amino acid chain Secondary is the folding or spiraling that occurs when molecules form H bonds

Tertiary involves a lot more bonding and folding

Quaternary is more than one chain combining to make a larger protein

Enzymes are proteins that speed up chemical reactions. If you didn’t have enzymes in your stomach to speed up digestion, the food would rot in your stomach because it would take so long!

Enzyme Action Enzymes have a specific shape Each enzyme catalyzes only one reaction

In each reaction, we have reactants and products. When we talk about enzyme catalyzed reactions, the reactants are often called substrate

Enzymes have an active site where the substrate fits (like a hand in a glove)

Another view (enzymes) Enzyme activity depends on the SHAPE of the active site.

Like all proteins, enzymes can be denatured (shape change) by changes in temperature or pH.)

So, when an enzyme is denatured, it no longer functions. (reactions slow way down!)

Remember, an enzyme is NOT USED UP (at all!) in a reaction.

Enzymes and Activation Energy It takes energy to make reactions happen. This is called activation energy.

An enzyme drastically lowers the activation energy needed in order to have a reaction proceed.

So, enzymes drastically speed up the rate of reactions

Nucleic acidsFunction: genetic material (RNA and

DNA)

The genetic code in your DNA determines how proteins are made (what amino acid sequence is used)

The nucleic acids in food are not considered a substance that the body

uses to gain energy.

Nucleic Acid structure Monomers are called nucleotides. They consist of a sugar + a phosphate + a base

Polymers are DNA and RNA strands

ATP! Adenosine triphosphate (ATP) is the molecule that cells break down to release energy.

Its structure looks a lot like a nucleic acid nucleotide, BUT it has three phosphate groups instead of one. Energy is stored in those phosphate bonds, and released for use when ATP becomes ADP (one bond broken)