AP Bio Ch.3 slides 1-19

In terms of science, what does the term "organic" mean?

Any compound that contains carbon atoms bonded to hydrogen atoms (C-H bonds)

Humans don’t have the cellulase enzyme to break down cellulose but is still useful because it is ____________________ and helps keep digestion healthy

dietary fiber

What is it about carbon's atomic structure that makes it the "building block of life"?

✅ Form 4 strong covalent bonds with other atoms

✅ Bond with many different elements (especially CHNOPS)

✅ Create long chains, rings, and complex structures

✅ Form single, double, or triple bonds

What are hydracarbons?

Organic molecules consisting of only carbon and hydrogen that are Non-polar (hydrophobic) and very stable molecules

What is a Functional Group

the components of organic molecules that are most commonly involved in chemical reactions

The structure and function of a polysaccharide are determined by?

its sugar monomers and the positions of glycosidic linkages.

Type: Glucose

Monomer/Polymer

Where found?

Monomer (simple sugar)

Found in all living cells as a primary energy source

Characteristics/Function of Glucose?

Main energy source for cells

Used to build larger carbohydrates

Type: Glycogen

Monomer/Polymer

Where found?

Polymer (made of glucose monomers)

Found in animals (liver and muscle cells) as energy storage

Carbohydrates monosaccharides are?

glucose, fructose

Carbohydrates disaccharides are?

Lactose and sucrose

Carbohydrates polysaccharides are?

Cellulose (plants)

Starch (plants)

Glycogen (animals)

Chitin (animals and fungi)

Monosaccharides function?

-fuel for cellular work in molecules

-raw material for making other organic molecules (amino acids)

-incorporated into di/polysaccharides

Polysaccharides function?

plant cell walls, energy storage, exoskeletons, fungal cell walls

Carbohydrates contain what CHNOPS?

C, H, O

What are the 6 most important elements in organic chemistry?

CHNOPS — the 6 key elements in most organic molecules

Because carbon can form 4 bonds, including with other carbon atoms, it can create what type of molecules?

molecules with stable, long chains and complex molecules — perfect for building life.

Why do hydrocarbons release a large amount of energy during reactions?

High-energy C-H bonds break → new stable bonds form → energy released

What happens to the bonds of hydracarbon during combustion?

During combustion or cellular respiration, these bonds break and form new, more stable bonds (like with oxygen).

In the combustion of hydracarbons, you're going from okay-stable bonds (C-H) → to super-stable bonds (C=O, O-H) That jump releases a lot of energy

.

Why do fats store so much energy?

Fats have long hydrocarbon tails made of many C-H bonds.These high-energy bonds release lots of energy when broken down (e.g., during cellular respiration).✅ That's why fats store more energy per gram than carbohydrates or proteins.

Why do bonds with less electron pull (like C-H) have higher potential energy compared to bonds with stronger electron pull (like O-H)?

The electrons that pull less want to move to be stable, stronger ones are already stable

Bonds with electrons that aren't held tightly have stored potential energy. When those electrons move to form stronger, more stable bonds what happens to energy?

When those electrons move to form stronger, more stable bonds, that stored energy is released.

This released energy can power processes like heat production, cellular work, or light emission.

What is an isomer?

compounds that have the same formula but different structures,

therefore having different properties and functions

The __________ and __________________ of functional groups give each molecule its unique properties. (?)

The number and arrangement of functional groups give each molecule its unique properties.

What is the carbon electron configuration?

Carbon has 4 valence electrons that are all unpaired because it has undergone excitation and hybridization.

What are the four most common elements that make up living things... What other elements are important and why?

Four most common :

Carbon (C)

Hydrogen (H)

Oxygen (O)

Nitrogen (N)

Other important ones :

Phosphorus (P) — important in DNA, RNA, and ATP, and phospholipids

Sulfur (S) — found in some amino acids

What's a Monomer?

A simple compound whose molecules can join together to form polymers

What's a Dimer

a compound whose molecules are composed of two identical monomers

What's a Polymer

A long molecule consisting of many similar or identical monomers linked together.

Three of the four classes of life's organic molecules make polymers. They are?

Carbohydrates

Proteins

Nucleic acids

What are the four classes of life's organic molecules?

Carbohydrates

Proteins

Nucleic acids

Lipids

What is Carbohydrate's monomer and polymer?

monosaccharide, polysaccharide

What is a condensation (dehydration) reaction?

➕ A condensation or dehydration reaction builds a polymer by joining monomers together.

➖ It removes a water molecule (H₂O) for each bond formed.

What is a hydrolysis reaction?

➖ A hydrolysis reaction breaks a polymer into monomers.

➕ It adds a water molecule (H₂O) to break the bonds.

How do condensation and hydrolysis reactions differ?

Condensation (dehydration) reactions build polymers by removing water, while hydrolysis reactions break polymers by adding water.

What three elements make up carbohydrates? What is their typical ratio?

Carbohydrates are made of Carbon (C), Hydrogen (H), and Oxygen (O). The typical ratio is 1:2:1 (C:H:O).

What type of bond connects two monosaccharides in a dehydration reaction?

A glycosidic linkage

Type: Starch

Monomer/Polymer?

Where found?

Polymer (made of glucose monomers)

Found in plants (energy storage)

Type: Chitin

Monomer/Polymer?

Where found?

Polymer : made of modified glucose monomers with nitrogen

Found in exoskeletons of arthropods and fungal cell walls

Characteristics/Function:

Provides structural support

Strong and flexible

What macromolecule is this?

Chitin

Type: Cellulose

Monomer/Polymer

Where found?

Polymer (made of glucose monomers)

Found in plant cell walls

Is cellulose digestible by humans?

No, the OHs are on opposite sides so the enzyme can't break down the linkages

Is starch digestable by humans?

Yes, the OHs are on the same side so the enzyme can break down the linkages

Which carbohydrates are polymers of glucose?

Starch, cellulose, and glycogen are all glucose polymers, but differ in their structure and function.

What are polysaccharides and what is there function?

the polymers of sugars, they have storage and structural roles.

Provides structural support to plants

Indigestible by most animals

What macro does this describe?

Cellulose

Quick energy storage and release in animals

More branched than starch

What macro does this describe?

Glycogen

Most carbohydrates can be recognized by what ending of their names?

-ose

When breaking down starch during digestion, what reaction occurs?

a hydrolysis reaction occurs.

What are two main reasons carbohydrates are needed for living organisms?

Energy Source: Carbohydrates are the primary and most immediate source of energy. Cells break down glucose (a simple carbohydrate) during cellular respiration to produce ATP, the energy currency of the cell.

Structural Support: Some carbohydrates provide structural components.

For example:

In plants, cellulose (a carbohydrate) strengthens cell walls.

In insects and fungi, _________ (a ________ carbohydrate) forms exoskeletons or cell walls.

In insects and fungi, chitin (a modified carbohydrate) forms exoskeletons or cell walls.

Why can't humans digest cellulose?

Humans lack cellulase, the enzyme needed to break β(1→4) bonds in cellulose.

The structure of β-glucose (due to -OH group orientation) makes the bonds different from those in digestible carbs like starch.

What simple sugar monosaccharide is made during photosynthesis and broken down during respiration?

Glucose

When humans have too many simple sugars in their blood, insulin is released to convert glucose into what polysaccharide?

Glycogen

Why are lipids not polymeric?

Because they aren’t made of repeating monomers