Macronutrients, Enzymes, and Digestive System Review

Macronutrients

Key Terms

• Steroids/Cholesterol

• Proteins

• Amino Acids

• Carbohydrates

• Mono/di/polysaccharides

• Dehydration synthesis

• Triglycerides

• Phospholipids

• Saturation/unsaturated fat

• Lipids

• Hydrolysis

• Polypeptide

• Coagulation

Macronutrients

• Lipids

• Proteins

• Carbohydrates

Makeup of Carbohydrates

• Carbon, hydrogen, and oxygen atoms.

Carbohydrate Types

Common Disaccharides and Formation

• Sucrose: Glucose + Fructose = Table Sugar

• Lactose: Glucose + Galactose = Milk Sugar

• Maltose: Glucose + Glucose

Common Polysaccharides

• Glycogen: Storage form of glucose in animals.

• Starch: Storage form of glucose in plants.

• Cellulose: Structural component of plant cell walls.

Dehydration Synthesis and Hydrolysis

• Dehydration Synthesis: Removes a water molecule to join monomers.

• Hydrolysis: Adds a water molecule to break polymers into monomers.

Makeup of Lipids

• Carbon, hydrogen, and oxygen.

Saturated vs. Unsaturated Fatty Acids

• Saturated Fatty Acids:

  • Carbon chain consists of only single bonds.

  • Allows for a more compact shape.

  • Solid at room temperature.

• Unsaturated Fatty Acids:

  • Contain at least one double bond in the carbon chain.

  • Creates a "kink" in the chain.

  • Cannot pack as tightly.

  • Liquid at room temperature.

Types of Lipids

Triglycerides

• Formed by joining three fatty acids to a glycerol molecule through dehydration synthesis.

• Can be saturated (derived from animals, fats) or unsaturated (derived from plants, oils).

• Function: Energy storage.

  • Excess energy is stored as triglycerides.

  • Broken down into carbon or fatty acids.

  • Provide insulation and protect body mass during periods of low caloric intake.

Phospholipids

• Structurally similar to triglycerides.

• One fatty acid tail is replaced by a phosphate group.

• Essential component of cell membranes.

• Amphipathic nature (hydrophilic and hydrophobic ends).

Cholesterol

• Lipid without fatty acid chain.

• Can produce vitamin D and produce hormones such as estrogen, testosterone, etc.

• Synthesized in the liver.

• Helps to maintain cell membrane structure.

• Can build up in arteries, leading to cardiovascular issues.

Protein Structure

1. Primary: Amino acid chains with linear arrangement.

2. Secondary: Amino acid chains coiled or folded due to hydrogen bonding.

3. Tertiary: The coiled molecule is further folded into a 3D shape.

4. Quaternary: Two or more proteins interact.

Denaturation and Coagulation

• Denaturation: Change in the shape of a protein due to physical or chemical factors.

  • Caused by physical or chemical factors.

  • Causes protein to unfold or uncoil, or change shape.

  • Changes protein's physical properties.

• Coagulation: Permanent change in the protein's shape.

  • Example: Egg white turning opaque when cooked.

Macronutrient Tests

• Iodine solution:

  • Tests for: Polysaccharides

  • Positive result: Dark blue/black color

• Biuret test

  • Turns blot when protein is detected.

Enzymes

• Made of protein.

• Act as catalysts to regulate chemical reactions.

Factors Influencing Enzyme Activity

• Temperature:

  • Enzymes have optimal temperatures.

  • Activity decreases at high temperatures (above 37^{\circ}C) due to denaturation.

• pH:

  • Enzymes have optimal pH ranges.

  • Pepsin thrives in low pH (acidic) environments.

  • Trypsin thrives in high pH (basic) environments.

• Substrate concentration:

  • Enzyme activity increases with substrate concentration until saturation is reached.

  • Enzyme binds to the substrate.

Digestive System

• Organs with food moving through them are:

  • Esophagus

  • Stomach

  • Large Intestine

  • Small Intestine

  • Rectum

• Accessory organs:

  • Salivary glands

  • Liver

  • Gallbladder

  • Pancreas

Macronutrient Movement Through Digestive Organs

Mouth

• Mechanical digestion: Chewing/mixing food with teeth/tongue.

• Chemical digestion: Salivary glands contain amylase (enzyme) which breaks down starch into disaccharides.

Esophagus

• Movement of food bolus by peristalsis (waves of contraction and relaxation).

• Walls contain mucus glands to lubricate food for easier passage.

Stomach

• Mechanical Digestion: Stomach churns up food

• Peristaltic contractions.

• Chemical Digestion: Stomach secretes gastric juice.

  • Gastric juice aids in food breakdown.

  • (HCl) kills bacteria in food.

  • Mucus protects the lining of the stomach

Small Intestine

• Peristaltic contractions.

• Major organ for nutrient absorption into bloodstream. Proteins, disaccharides and lipids are absorbed into the blood stream.

• Duodenum, jejunum, and ileum are major sections.

Large Intestine

• Colon and rectum function by absorbing water and electrolytes.

• No digestion of macronutrients.

Rectum

• Stores waste material from the colon.

• Prepares for defecation.

• Does not perform chemical digestion or absorption of macronutrients.

Macronutrients

Key Terms

Steroids/Cholesterol

Proteins

Amino Acids

Carbohydrates

Mono/di/polysaccharides

Dehydration synthesis

Triglycerides

Phospholipids

Saturation/unsaturated fat

Lipids

Hydrolysis

Polypeptide

Coagulation

Macronutrients

Lipids

Proteins

Carbohydrates

Makeup of Carbohydrates

Carbon, hydrogen, and oxygen atoms.

Carbohydrate Types

Type

Definition

Example

Monosaccharide

Contains 3-8 carbons.

Glucose and Fructose

Disaccharide

Two monosaccharide units joined together.

Sucrose and Lactose

Polysaccharide

Many monosaccharide units linked together. Can be branched or unbranched chains.

Starch, Glycogen, and Cellulose

Common Disaccharides and Formation

Sucrose: Glucose + Fructose = Table Sugar

Lactose: Glucose + Galactose = Milk Sugar

Maltose: Glucose + Glucose

Common Polysaccharides

Glycogen: Storage form of glucose in animals.

Starch: Storage form of glucose in plants.

Cellulose: Structural component of plant cell walls.

Dehydration Synthesis and Hydrolysis

Dehydration Synthesis: Removes a water molecule to join monomers.

Hydrolysis: Adds a water molecule to break polymers into monomers.

Makeup of Lipids

Carbon, hydrogen, and oxygen.

Saturated vs. Unsaturated Fatty Acids

Saturated Fatty Acids:

Carbon chain consists of only single bonds.

Allows for a more compact shape.

Solid at room temperature.

Unsaturated Fatty Acids:

Contain at least one double bond in the carbon chain.

Creates a "kink" in the chain.

Cannot pack as tightly.

Liquid at room temperature.

Types of Lipids

Triglycerides

Formed by joining three fatty acids to a glycerol molecule through dehydration synthesis.

Can be saturated (derived from animals, fats) or unsaturated (derived from plants, oils).

Function: Energy storage.

Excess energy is stored as triglycerides.

Broken down into carbon or fatty acids.

Provide insulation and protect body mass during periods of low caloric intake.

Phospholipids

Structurally similar to triglycerides.

One fatty acid tail is replaced by a phosphate group.

Essential component of cell membranes.

Amphipathic nature (hydrophilic and hydrophobic ends).

Cholesterol

Lipid without fatty acid chain.

Can produce vitamin D and produce hormones such as estrogen, testosterone, etc.

Synthesized in the liver.

Helps to maintain cell membrane structure.

Can build up in arteries, leading to cardiovascular issues.

Protein Structure

1. Primary: Amino acid chains with linear arrangement.

2. Secondary: Amino acid chains coiled or folded due to hydrogen bonding.

3. Tertiary: The coiled molecule is further folded into a 3D shape.

4. Quaternary: Two or more proteins interact.

Denaturation and Coagulation

Denaturation: Change in the shape of a protein due to physical or chemical factors.

Caused by physical or chemical factors.

Causes protein to unfold or uncoil, or change shape.

Changes protein's physical properties.

Coagulation: Permanent change in the protein's shape.

Example: Egg white turning opaque when cooked.

Macronutrient Tests

Iodine solution:

Tests for: Polysaccharides

Positive result: Dark blue/black color

Biuret test

Turns blot when protein is detected.

Enzymes

Made of protein.

Act as catalysts to regulate chemical reactions.

Factors Influencing Enzyme Activity

Temperature:

Enzymes have optimal temperatures.

Activity decreases at high temperatures (above 37^{\circ}C) due to denaturation.

pH:

Enzymes have optimal pH ranges.

Pepsin thrives in low pH (acidic) environments.

Trypsin thrives in high pH (basic) environments.

Substrate concentration:

Enzyme activity increases with substrate concentration until saturation is reached.

Enzyme binds to the substrate.

Digestive System

Organs with food moving through them are:

Esophagus

Stomach

Large Intestine

Small Intestine

Rectum

Accessory organs:

Salivary glands

Liver

Gallbladder

Pancreas

Macronutrient Movement Through Digestive Organs

Mouth

Mechanical digestion: Chewing/mixing food with teeth/tongue.

Chemical digestion: Salivary glands contain amylase (enzyme) which breaks down starch into disaccharides.

Esophagus

Movement of food bolus by peristalsis (waves of contraction and relaxation).

Walls contain mucus glands to lubricate food for easier passage.

Stomach

Mechanical Digestion: Stomach churns up food

Peristaltic contractions.

Chemical Digestion: Stomach secretes gastric juice.

Gastric juice aids in food breakdown.

(HCl) kills bacteria in food.

Mucus protects the lining of the stomach

Small Intestine

Peristaltic contractions.