Aim: How do enzymes work?

HW #16

Read pages 49-53

Take notes by writing two summary sentences for each page you read.

Enzymes are a particular kind of protein that have

the ability to catalyze reactions in living organisms.

Proteins are very long chain molecules made up of amino acid building blocks.

The protein chain is folded in a complex three dimensional shape known as its tertiary

structure.

What do you know about amino acids?

There are 20 amino acids.

They differ by what is on the central carbon.

All amino acids contain a N atom in the chemical formula.

Amino acids come into our body as food that we eat.

Proteins are made up of amino acids. Twenty amino acids arranged in an endless array yields an infinite number of proteins.

Proteins are made up of amino acids

Proteins have many functions….

• structural support (collagen)

Proteins have many functions….

• parts of cell membranes transport molecules

Protein channel

proteins

Lipid bilayer

CarbohydrateLipid bilayer

Proteins have many functions….

• Hormones• Protein molecules

bind to receptors on the surface of "target" cells

Somatropin (GH)

Proteins have many functions….

• regulate body metabolism

• antibodies of immune system

• toxins in some microorganisms

• catalyze chemical reactions as ENZYMES

Proteins have many functions….

• actin and myosin – muscle contraction

Proteins have many functions….

• regulate the cell cycle

Groups

List the four proteins that regulate the cell cycle

• There are more than 3,000 known enzymes in the human body. The body’s ability to function and repair itself is directly related to the strength and number of enzymes that are present. Every second, they are changing and renewing, sometimes at unbelievable rates.

The enzyme shape fits the shape of the substance it will break down.

Enzymes work in specific ways

Substrate is what will be digested (broken down) by the specific enzyme

Enzyme action

The enzyme and substrate come together at the active site.

The shape of the enzyme fits the shape of the substrate

Digestive enzymes

..break down larger molecules into smaller ones

Products are …

..different from what we started with

Real life application of enzymes

• Many biological washing powders contain enzymes to help with the removal of stains. The enzyme may be a protease to break down protein stains or a lipase to break down fat and oil (lipids) stains.

Digestion of starch

Salivary Amylase

This enzyme breaks the bonds that hold the polymer together

Digestion of starch produces simple sugars

Techniques scientists use to visualize molecular structures include:

• Spectroscopy (UV-Vis).

• Fluorescence.

• Circular dichroism (CD).

• Differential scanning calorimetry (DSC).

• Nuclear magnetic resonance (NMR).

• Analytical ultra centrifugation (AUC).

• Small angle x-ray spectroscopy.

Enzymes are proteins

Enzymes are needed for synthesis also.

Protease digests proteins

• All enzymes have a particular shape that fits the molecules they act on.

The Digestive EnzymesSite

Mouth

Stomach

Small intestine(from pancreas)

Small intestine

Site

Mouth

Stomach

Small intestine(from pancreas)

Small intestine

EnzymeEnzyme Role in DigestionRole in Digestion

Section 38-2

Salivary amylase

Pepsin

Amylase

Trypsin

Lipase

Maltase, sucrase, lactase

Peptidase

Breaks down starches into disaccharides

Breaks down proteins into large peptides

Continues the breakdown of starch

Continues the breakdown of protein

Breaks down fat

Breaks down remaining disaccharides into monosaccharides

Breaks down dipeptides into amino acids.