CELLS 1.1 Biomolecules- Pre AP Biology Study Notes - New Syllabus.

CELLS 1.1 Biomolecules- Pre AP Biology Study Notes

CELLS 1.1 Biomolecules- Pre AP Biology Study Notes – New Syllabus.

LEARNING OBJECTIVE

CELLS 1.1(a) Differentiate between the major macromolecules based on their structure and/or function.
CELLS 1.2(a) Explain the role macromolecules play in supporting cellular function.

Key Concepts:

CELLS 1.1.1 The four classes of organic macromolecules are proteins, carbohydrates, lipids, and nucleic acids. Each class has unique chemical structures.
a. These organic macromolecules are primarily made up of just a few elements—carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus.
b. Most macromolecules are polymers that are made up of specific, smaller subunits called monomers.
CELLS 1.2.1 Each class of macromolecule carries out specific functions in biological systems.
a. Carbohydrates serve as the primary source of energy for organisms in the forms of glycogen and starch, and as structural support in plant cell walls in the form of cellulose.
b. Lipids are used as a source of energy and as building blocks of biological membranes.
c. Proteins are responsible for numerous cellular functions, such as catalyzing reactions, providing structure, and aiding in cell transport and signaling.
d. Nucleic acids are responsible for storing and transferring genetic information in the form of DNA and RNA.

Pre AP Biology-Concise Summary Notes- All Topics

Differentiation of Major Macromolecules Based on Structure and Function

🌱 Introduction

Living cells are made up of four major classes of organic macromolecules.
Although all macromolecules are carbon-based, they differ clearly in their chemical structure and biological function.

📌 What Does “Differentiate” Mean in Biology?

To differentiate means to:

Compare structure
Compare monomers
Compare elements
Compare functions
Identify unique roles of each macromolecule

🧬 Overview of the Four Major Macromolecules

Macromolecule	Basic Role
Carbohydrates	Energy and structural support
Lipids	Energy storage and membranes
Proteins	Cellular work and regulation
Nucleic acids	Genetic information

1. Carbohydrates

Structural Characteristics

Elements present: Carbon, Hydrogen, Oxygen
Hydrogen to oxygen ratio is usually 2:1
Built from repeating monosaccharides
Form long chains called polysaccharides

Examples of monomers:

Glucose
Fructose

Functional Characteristics

Carbohydrates mainly function as energy molecules.

Functions:

Immediate energy for cells (glucose)
Energy storage
Glycogen in animals
Starch in plants
Structural support
Cellulose in plant cell walls

Key point:
Carbohydrates provide short-term, quickly available energy.

2. Lipids

Structural Characteristics

Elements present: Carbon, Hydrogen, Oxygen
Contain much less oxygen than carbohydrates
Not true polymers
Composed of fatty acids and glycerol
Hydrophobic (do not dissolve in water)

📌 Examples:

Fats
Oils
Phospholipids
Steroids

⚙️ Functional Characteristics

Lipids perform long-term energy storage and structural roles.

Functions:

Store large amounts of energy
Form cell membranes (phospholipid bilayer)
Provide insulation and protection
Act as hormones (steroids)

Key point:
Lipids store more energy per gram than carbohydrates.

3. Proteins

Structural Characteristics

Elements present: Carbon, Hydrogen, Oxygen, Nitrogen
Sometimes contain Sulfur
Built from amino acid monomers
Amino acids are linked by peptide bonds
Fold into complex 3-dimensional shapes

Important:
Protein structure determines protein function.

⚙️ Functional Characteristics

Proteins are responsible for most activities within the cell.

Functions:

Enzymes speed up chemical reactions
Structural proteins provide support
Transport proteins move substances
Signaling proteins enable communication
Defense proteins protect against pathogens

Key point:
Proteins are the working molecules of the cell.

4. Nucleic Acids

Structural Characteristics

Elements present: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus
Built from nucleotide monomers
Each nucleotide has:
Sugar
Phosphate group
Nitrogenous base

Types:

⚙️ Functional Characteristics

Nucleic acids handle genetic information.

Functions:

DNA stores hereditary information
RNA transfers genetic instructions and helps make proteins

Key point:
Without nucleic acids, cells cannot control or reproduce.

📊 Comparison Table: Structure and Function

Feature	Carbohydrates	Lipids	Proteins	Nucleic Acids
Main elements	C, H, O	C, H, O	C, H, O, N (S)	C, H, O, N, P
Monomer	Monosaccharide	None (fatty acids)	Amino acid	Nucleotide
Polymer	Polysaccharide	Not true polymers	Polypeptide	Polynucleotide
Main function	Quick energy, structure	Long-term energy, membranes	Enzymes, cell functions	Genetic information
Example	Glucose	Phospholipid	Enzyme	DNA

🧠 How They Differ Clearly

Carbohydrates focus on energy and structure
Lipids focus on energy storage and membranes
Proteins focus on cellular processes
Nucleic acids focus on information storage
Each macromolecule has a unique structure that matches its function

📦 Quick Recap
All macromolecules are carbon-based
Carbohydrates provide quick energy and support
Lipids store energy and form membranes
Proteins perform most cellular tasks
Nucleic acids store and transmit genetic information
Structure determines function in all macromolecules

Role of Macromolecules in Supporting Cellular Function

🌱 Introduction

Cells are the basic units of life, but they cannot survive or function on their own without macromolecules.
Each class of macromolecule performs specific roles that allow cells to obtain energy, maintain structure, regulate processes, and store information.
Macromolecules work together to support all cellular functions essential for life.

📌 What Does “Supporting Cellular Function” Mean?

Supporting cellular function includes:

Supplying energy
Maintaining cell structure
Regulating chemical reactions
Enabling communication
Storing and using genetic information

Without macromolecules, cells cannot:

Grow
Repair
Reproduce
Respond to their environment

🧬 Role of Each Macromolecule in Cells

1. Carbohydrates and Cellular Function

Energy Supply

Carbohydrates are the primary and immediate energy source for cells.

Glucose is broken down during cellular respiration
Releases energy needed for:
Active transport
Cell division
Biosynthesis

Key point:
Cells rely on carbohydrates for quick and efficient energy.

Structural Support

Some carbohydrates provide physical support to cells.

Cellulose forms plant cell walls
Maintains cell shape
Prevents cell bursting

This structural role is essential for plant cell stability.

2. Lipids and Cellular Function

Long-Term Energy Storage

Lipids store large amounts of energy.

Used when carbohydrate reserves are low
Provide sustained energy for cells

Important note:
Lipids yield more energy per gram than carbohydrates.

Cell Membrane Formation

Lipids are critical for forming biological membranes.

Phospholipids form the cell membrane
Create a selectively permeable barrier
Control movement of substances in and out of the cell

Without lipids, cells cannot maintain internal balance.

Protection and Insulation

Lipids also:

Protect organs
Insulate cells
Maintain temperature stability

3. Proteins and Cellular Function

Proteins are the most diverse and functionally important macromolecules in cells.

Enzymes (Catalysis)

Enzymes are proteins
Speed up chemical reactions
Make metabolism efficient

Key idea:
Without enzymes, reactions would be too slow to sustain life.

Structural Support

Proteins help maintain cell shape and structure.

Form cytoskeleton components
Strengthen tissues

Transport

Proteins move substances:

Across membranes
Within cells

Examples:

Channel proteins
Carrier proteins

Cell Signaling and Communication

Proteins act as:

Receptors
Signaling molecules

Allow cells to:

Detect signals
Respond to their environment

Defense

Some proteins:

Recognize pathogens
Protect cells from infection

4. Nucleic Acids and Cellular Function

Genetic Information Storage

Nucleic acids control cell identity and activity.

DNA stores genetic instructions
Determines cell structure and function

Protein Synthesis

Nucleic acids guide protein production.

RNA carries instructions from DNA
Ensures correct proteins are made

Key point:
Without nucleic acids, cells cannot:

Make proteins
Divide
Pass on traits

🔄 How Macromolecules Work Together in Cells

Macromolecules do not act alone.

Example of coordination:

DNA stores instructions
RNA transfers information
Proteins perform the function
Carbohydrates and lipids supply energy

Cellular function depends on integration of all macromolecules.

📊 Summary Table: Macromolecules and Cellular Roles

Macromolecule	Role in Cellular Function
Carbohydrates	Immediate energy, structure
Lipids	Long-term energy, membranes
Proteins	Enzymes, transport, signaling
Nucleic acids	Genetic control, protein synthesis

🧠 Key Statements

Each macromolecule has a specific cellular role
Structure determines function
Cells require all four macromolecules to survive

📦 Quick Recap
Carbohydrates supply quick energy and support
Lipids store energy and form membranes
Proteins control and regulate cellular activities
Nucleic acids store and use genetic information
All macromolecules work together to sustain life

CELLS 1.1 Biomolecules- Pre AP Biology Study Notes - New Syllabus.