Biology 20 AP Final Exam Review

What does the Digestive System do?

Breaks down ingested materials into chemical units.

What are macromolecules?

Large and complex, organic molecules often made from similar subunits linked together.

What are the Subunits in macromolecules?

Proteins, lipids, nucleic acid and carbohydrates.

How are macromolecules made?

The subunits are joined together using Dehydration Synthesis.

How does Dehydration Synthesis work?

Enzymes carry out the reaction by bringing water out. (Removal of H’s in Hydroxyl -OH- groups)

How are Macromolecules Broken down?

Through Hydrolysis.

What is Hydrolysis?

The Process of adding water with the use of enzymes.

What are main functions of carbohydrates?

Short of long term energy storage.

What do Carbohydrates always contain?

C, H, O

What is the certain ratio of C, H, O in carbohydrates?

2H:1O:1C

How many carbons do simple sugars have?

3 to 7

What are the types of simple sugars?

• Monosaccharides

• Disaccharides

• Polysaccharides

• Glycogen

• Starch

• Cellulose

What are Monosaccharides?

Carbs made up of 1 simple sugar.

What are Disaccharides?

Carbs made up of 2 simple sugars.

What are Polysaccharides?

Carbs made up of many simple sugars linked together.

What is glycogen?

The storage of glucose.

Where do animals store glucose?

In their livers.

What is Starch?

Energy storage in plants. (Amylose)

What is cellulose?

Composes cell walls in plants. (Fibre)

Solubiltity of lipids in water?

Insoluble in water.

Do lipids have energy?

Yes, they contain the most amount of energy, compared to other biological molecules.

How many more grams of energy do lipids store than other biological molecules?

2.25 times more energy per gram.

What are the three types of lipids called?

1. Triglycerides

2. Phospholipids

3. Steroids

How is Triglyceride made?

One glycerol and three fatty acid.

What is the function of triglyceride?

Long term energy storage and insulation

Solubility of Triglycerides?

Insoluble in Water.

What is the structure of Phospholipids?

One glycerol molecule, two fatty acids and one phosphate group.

Function of Phospholipids?

Makes up the cell membrane, forming a bilayer controlling what properties enter and exit the cell.

Solubility of Phospholipids?

Amphipathic - has both hydrophobic and hydrophilic areas.

Structure of Steroids?

Four fused carbon rings.

Functions of Steroids?

Serves as hormones and are involved in maintaining cell membrane stability.

Solubility of Steroids?

Insoluble in water but soluble in lipids.

What is a saturated fatty acid?

Has no double bonds between its carbon atoms, allowing it to hold the maximum number of hydrogen atoms. It causes fat to be liquid at room temperature.

What is an unsaturated fatty acid?

Has double bonds in between carbon atoms, leaving room for additional hydrogen atoms. It causes fat to be solid at room temperature.

What are proteins?

Composed of amino acids linked together by peptide bonds.

Why are proteins important?

They serve many functions

Composition of amino acids - subunit of amino acids?

A central carbon atom bonded to a hydrogen atom and three other groups of atoms, called amino group, acid group and R group.

Which part of the amino acid determines its identity?

R group.

What is the amino acid?

monomer

What is the protein?

polymer

How many amino acids are there?

20

How many can the body make?

11

How many have to be ingested?

9

What is a peptide bond?

What is the chain called if the amino acids are bonded?

A polypeptide

What is another name for a protein?

What determines the properties and functions of a protein?

The three dimensional structure.

How many structures are there?

30

How do R groups affect the solubility of proteins?

Some R groups are electrically charged making them attracted to water (enzymes and hemoglobin) making it soluble in water. On the other hand, R groups in keratin are not electrically charged, repelling the water allowing for its insolubility..

Purpose of Nucleic acids?

Composes the heriditary material, directing growth and development of all organisms using a chemical code. Determines a cells functions and its characteristics.

What are the two types of nucleic acid?

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

What are the subunits for nucleic acid?

Nucleotides

What are the 3 different parts of nucleotides?

Nitrogen-containing base, phosphate group and a five-carbon simple sugar.

What is five-carbon simple sugar found in RNA?

Ribose

What is the five-carbon simple sugar found in DNA

Deoxyribose

Purpose of Vitamins and Minerals?

Essential to the structure and function of the cells. Key component to chemical reactions, breaking down and synthesizing compounds and yielding energy.

What are Vitamins?

Organic compounds that are needed in small amounts, serving as a co enzyme (helps an enzyme function.) and works in tissue development, growth and disease resistance.

What are minerals?

Inorganic compounds, needed in small amounts, which builds bones and cartillage and allows for reactions to happen. Makes up hemoglobin, hormones, enzymes and vitamins.

Enzymes?

Specific to a substrate, are not used up in a reaction, biological catalyst, speeds up reactions by lowering activation rate, used over and does not react.

What are substrates?

Reactants that bind to the active site on the enzyme, causing substrate bonds to change.

What affects enzyme rates?

Temperature: 37 degrees, pH, substrate size

What will happen if temperatures are too high and pH is not adequate?

The enzyme will denature.

What is a catalyst?

Speeds up a reaction but is not used up in it.

What is a competitive inhibitor?

Attaches to enzyme site preventing reactions.

What is a Non-competitive inhibitor?

Attaches to enzyme to alter the active site, preventing the binding of a substrate.

What are accessory organs?

Structures that aid digestion.

What are the accessory organs in the digestive system?

Salivary Glands, Liver, Gall Bladder and Pancreas.

Salivary Glands?

Secretes starch digesting enzymes (salivary amylase)

Liver?

Creates bile.

What is Bile?

A detergent-like substance that facilitates digestion of fats.

Gall Bladder?

Stores bile until needed.

Pancreas?

Creates enzymes to digest macromolecules, secreting bicarbonate to neutralize stomach acid that enters small intestine.

Which organs are found in the Digestive tract (Organs that contain food)?

Mouth, Esophagus, stomach, small intestine, large intestine (colon), rectum and anus

Mouth:

Chews food and mixes it with saliva.

Esophagus:

A tube guiding food to the stomach.

Stomach:

Adds acid, enzymes and fluids; churns, mixes and grinds food to a liquid mass.

Small Intestine:

Secretes enzymes that digest macromolecules; absorbs hydrolyzed molecules into bloodstream.

Large Intestine:

Absorbs water and salts; passes remaining undigested material and some water out of body.

Rectum:

Stores waste before its elimination?

Anus:

Holds rectum closed; opens to allow elimination.

Physical Digestion in the Mouth?

Teeth grinds food into a bolus, increasing the surface area for chemical digestion.

Chemical Digestion in the Mouth

Salivary amylase from the salivary glands chemically breaks down starches into simple sugars. It also lubricate the mouth to assist in swallowing.

Taste:

The taste buds on the tongue use chemical receptors to to identify the taste of specific chemicals in our food.

What is the esophagus?

a smooth

How does the esophagus move the bolus?

Through waves of muscle contractions called peristalsis, pushing the bolus toward the stomach.

Food in the Stomach?

Entry of food into the stomach is controlled by the esophageal sphincter (cardiac sphincter).

Where is the initial site of protein?

In the stomach.

How much can the stomach hold?

500 mL of corrosive gastric juices and 1.5 L of food.

Physical Digestion in the stomach:

Peristalsis churns and breaks up food into smaller pieces. These pieces mix with gastric juices to produce chyme.

What are gastric juices?

Water, mucus, salt, hydrochloric acid and enzymes that have a pH of 1-3

Chemical Digestion in the Stomach:

The Gastric Juices helps to soften and break down proteins in chyme and kills bacteria.

What do enzymes do?

Pepsin Hydrolyzes (breaks down) proteins that turns into polypeptides.

What prevents the stomach from digesting itself?

1. Gastric juices are not secreted until food is present

2. Mucus from the cells prevent the gastric juices from harming the stomach lining

3. Protein digesting enzyme, pepsin, stays inactive until gastric juices are present.

Process of Protein digestion?

Pepsinogen turns into pepsin, breaking down proteins, after being activated by HCl (gastric juices).

What is absorbed in the Stomach?

Small amounts of water salt, anti-inflammatory medicines and alcohol

What is not absorbed in the Stomach?

Chyme

Which sphincter controls the exit of chyme into the small intestine?

Pyloric Sphincter

How many times longer is the small intestine compared to the large one?

4x

Function of the small intestine?

Digest the macromolecules and absorb their subunits (Carbohydrates, Nucleic Acid, Lipids and Proteins)

Regions of the Small intestine?

1. Duodenum

2. Jejunum

3. Ileum