Biology grade 10

Biomolecules and Their Role in Life

Building blocks of life and energy storage

Composition

Made of carbon hydrogen oxygen and nitrogen

Monomers and Polymers

Small units called monomers join to form large polymers

Water Solubility

Some biomolecules dissolve in water others do not

Lipids

Used for energy storage and cell membranes

Saturated Fats

No double bonds solid at room temperature

Unsaturated Fats

Have double bonds liquid at room temperature

Phospholipids

Have hydrophilic heads and hydrophobic tails form membranes

Cholesterol

Stabilizes membranes and makes sex hormones

ATP

Main energy carrier composed of adenine ribose and three phosphates

Amino Acids

Build proteins and determine their shape and function

Essential Amino Acids

Must be obtained from diet

Nonessential Amino Acids

Made by the body

Homeostasis and Feedback Mechanisms

Maintaining stable internal conditions

Regulated Factors

Temperature glucose water and pH levels

Homeostatic Control System

Receptor detects change control center processes effector responds

Negative Feedback

Reverses a change such as temperature or blood sugar control

Positive Feedback

Amplifies a change such as childbirth contractions

Cooling Mechanisms

Sweating and vasodilation widen blood vessels

Warming Mechanisms

Shivering goosebumps and vasoconstriction narrow vessels

High Blood Sugar

Insulin released to store glucose as glycogen

Low Blood Sugar

Glucagon released to break glycogen into glucose

Coordination Between Systems

Nervous and endocrine systems maintain balance

Cell Theory and Structure

Cells are the basic unit of life

Robert Hooke

Discovered cells in cork

Anton van Leeuwenhoek

Observed living microorganisms

Cell Theory Principles

All organisms made of cells cells are basic units cells come from existing cells

Prokaryotic Cells

No nucleus or membrane organelles such as bacteria

Eukaryotic Cells

Have nucleus and organelles such as plant and animal cells

Nucleus

Controls cell and stores DNA

Mitochondria

Produces ATP energy

Ribosomes

Make proteins

Rough ER

Modifies and transports proteins

Smooth ER

Makes lipids and detoxifies

Golgi Apparatus

Packages and ships proteins

Plasma Membrane

Controls what enters and leaves cell

Phospholipid Bilayer

Has hydrophilic heads and hydrophobic tails

Membrane Proteins

Help with transport and communication

Cholesterol in Membrane

Maintains flexibility and stability

Cell Transport and Movement

How cells balance with environment

Passive Transport

Moves substances without energy from high to low concentration

Diffusion

Molecules move from high to low concentration

Osmosis

Water moves through a membrane

Facilitated Diffusion

Proteins help move larger or charged molecules

Active Transport

Uses ATP to move materials against gradient

Sodium Potassium Pump

Moves sodium out and potassium in using ATP

Diffusion Factors

Rate depends on temperature surface area and concentration gradient

Primary Active Transport

Directly uses ATP for transport

Secondary Active Transport

Uses energy from another gradient

Hypotonic

Water enters cell causing it to swell

Isotonic

Equal water movement no net change