Digestive enzymes play specific roles in breaking down different types of nutrients. Each enzyme has a particular substrate it acts upon and produces specific products.

Vocabulary: Substrate - the substance upon which an enzyme acts.

The three main digestive enzymes are:

• Amylase: Converts starch to glucose
• Protease: Breaks down proteins into amino acids
• Lipase: Breaks down lipids into glycerol and fatty acids

Definition: Enzymes are biological catalysts that speed up chemical reactions in the body.

Food testing involves specific chemical reagents to identify different nutrients. Each test has distinct positive and negative results.

Example: Benedict's test for simple sugars shows an orange/green color when positive and remains blue when negative.

The main food tests include:

• Benedict's test for simple sugars
• Iodine test for starch
• Ethanol test for lipids
• Biuret test for proteins

Highlight: Each test has a specific color change indicating the presence or absence of the nutrient.

Blood consists of several components, each with specific functions essential for life. Red blood cells transport oxygen, white blood cells fight infection, and platelets help in blood clotting.

Definition: Plasma is the liquid component of blood that transports various substances including glucose, hormones, and waste products.

Highlight: White blood cells create antibodies and antitoxins to protect the body from infection.

Coronary heart disease occurs when coronary arteries become blocked with fatty deposits, leading to reduced blood flow to heart muscles.

Definition: Coronary heart disease is a condition where reduced blood flow to the heart leads to decreased oxygen supply and reduced energy production.

Highlight: The reduction in blood flow affects the heart's ability to contract effectively.

Blood vessels are specialized structures that transport blood throughout the body. Arteries and veins have different characteristics based on their functions.

Definition: Arteries carry blood away from the heart at high pressure, while veins return blood to the heart at lower pressure.

Highlight: Arterial walls are thicker than venous walls due to the higher pressure they must withstand.

The digestive system is a complex network of organs working together to break down food into usable nutrients. Each organ has specific functions and produces different enzymes essential for digestion. The process begins in the mouth with salivary amylase and continues through various organs including the stomach, liver, pancreas, and intestines.

Definition: The digestive system is responsible for breaking down food and absorbing nutrients into the bloodstream.

Highlight: The liver produces bile which serves two crucial functions: neutralizing stomach acid and emulsifying fats.

Example: The stomach produces both hydrochloric acid and pepsin enzyme, creating the perfect environment for protein digestion.