INTRODUCTION TO
BIOLOGY
WHAT IS A LIVING ORGANISM?
HOW ARE LIVING THINGS DIFFERENT
FROM NONLIVING THINGS?
• Organization
• The ability to grow and develop
• The ability to respond to the environment
• The ability to reproduce
ORGANIZATION
• An organism’s body is organized to fit
its needs.
• Some bodies are simple because their function is
simple; some are much more complex.
GROWING/DEVELOPING
• Some organisms change from birth to
their adult stage, while others stay
about the same.
RESPONDING TO THE ENVIRONMENT
• Organisms respond to the world
around them.
REPRODUCING
• Living organisms have the ability to
create new organisms similar to
themselves; offspring.
BASIC NEEDS OF LIVING ORGANISMS
• Energy
• Comes from the sun
• Remember: producer vs. consumer
• Materials
• Carbon dioxide, nitrogen, oxygen, and water
• Living space
• Space to live and grow.
UNICELLULAR VS. MULTICELLULAR
• Some organisms are made of only one cell:
unicellular
• Others are made of many cells: multicellular
• The needs and properties of both types are
the same.
CELLS AND HEREDITY
CHAPTER 1: INTRODUCTION TO CELLS
LESSON 1: DISCOVERING CELLS
WHAT ARE CELLS?
• Cells form the parts of an organism and
carry out many functions.
• In other words, they are the basic unit of
structure and function in all living things.
CELLS AND STRUCTURE
• The structure of a living thing is determined
by the different ways the cells are put
together.
CELLS AND FUNCTION
• Living things must be able to live, grow, and
reproduce to survive.
• In order to do this, they must have ways to
get oxygen, food, and water and a way to
get rid of waste.
• These processes are controlled by cells.
THE CELL THEORY
• Cell theory: widely accepted explanation of
the relationship between cells and living
things.
• All living things are made of cells.
• Cells are the basic unit of life.
• All cells are produced from other cells.
THE CELL THEORY HISTORY
• 1663: Robert Hooke observed cork and discovered
the name for cells.
• 1674: Anton van Leeuwenhoek observed living cells
in motion.
• 1838: Matthias Schleiden said all plants are made of
cells.
• 1839: Theodor Schwann said all animals are made
of cells.
• 1855: Rudolf Virchow said new cells only come from
other cells.
MICROSCOPES
• Microscope: an instrument that makes small objects
look larger.
• Some use light and lenses, others use beams of
electrons.
• A compound microscope uses two lenses to
magnify an object; the total magnification can be
found by multiplying the two lenses.
MICROSCOPES
• Resolution: the degree to which two separate
structure that are close together can be
distinguished.
• Better resolution shows more details.
• Resolution improves with higher magnification.
MICROSCOPES
• Electron microscopes use beams of electrons to
magnify objects.
• Generally have higher magnification and better
resolution than light microscopes, making them
better for smaller objects.
CELLS AND HEREDITY
CHAPTER 1: INTRODUCTION TO CELLS
LESSON 2: LOOKING INSIDE CELLS
THE PARTS OF A CELL
• Plant and animal cells have many of the
same organelles, or parts that make up a
cell.
• Each organelle has a unique structure and
function that helps the cell survive.
CELL MEMBRANE
• controls what goes in and out of the cell, like
a screen.
• Allows food, water, etc. in and keeps
harmful materials out.
• Found in both plants and animals.
NUCLEUS
• A cell’s control center, like a brain.
• Contains chromatin (DNA) to direct the cell’s
function.
• Contains nucleolus, which is where ribosomes are
made.
• Found in both plants and animals.
RIBOSOMES
• Small structures that make protein.
• Made in the nucleus, but travel throughout
the cell.
• Found in both plants and animals.
CYTOPLASM
• Clear, gel-like fluid that fills the region
between the cell membrane and the
nucleus.
• Moves constantly, carrying organelles
around the cell.
• Found in both plants and animals.
MITOCHONDRIA
• Convert energy in food to energy that can
be used to live.
• The “powerhouse” – “Mighty Mitochondria”
• Found in both plants and animals.
ENDOPLASMIC RETICULUM (ER)
• A maze-like structure.
• Some parts hold ribosomes (rough ER), while
others do not (smooth ER).
• Found in both plants and animals.
GOLGI APPARATUS
• Receives proteins and other materials from
the ER, packages them, and distributes
them.
• Found in both plants and animals.
VACUOLES
• Stores food, water, and other materials,
including waste.
• Found in both plants and some animals.
• Plants generally have one large, central vacuole.
CELL WALL
• An extra layer of protection outside of the
cell membrane.
• Made of cellulose.
• Found in plants only.
CHLOROPLASTS
• Green structures that make a plant green.
• Contains chlorophyll.
• Where photosynthesis occurs (captures
sunlight and turns it into food).
• Found in plants only.
LYSOSOME
• Break down large food particles into smaller
ones.
• Also recycle old cell parts.
• Found in animals only.
ANIMAL AND PLANT CELLS
Plants ONLY
Both
Animals ONLY
Cell wall
Cell membrane
Lysosome
Chloroplasts
Nucleus
Sometimes
vacuoles
Central Vacuole
Cytoplasm
Mitochondria
ER
Ribosomes
Golgi Apparatus
UNICELLULAR VS. MULTICELLULAR
• In single-celled, one cell performs ALL
functions.
• In multi-cellular, different cells perform
different functions.
• They are specialized to do specific jobs.
SPECIALIZED CELLS
• Multicellular organisms have different types
of cells to perform different jobs.
• Red blood cells carry oxygen.
• Nerve cells transmit messages.
LEVELS OF ORGANIZATION
• Begins with the cell.
• Cells that perform the same job join
together to form tissue.
• The tissues join together to make an organ,
and organs that work together form an
organ system.
ORGAN SYSTEMS LEAD TO ORGANISMS
• Different organ systems have specific
purposes in an organism.
Nervous: respond to environment
Muscular: movement and heat
Respiratory: inhale O2 and exhale CO2
Circulatory: delivers O2 in blood and remove CO2
in blood
• Digestive: breaks down food
•
•
•
•
CELLS AND HEREDITY
CHAPTER 1: INTRODUCTION TO CELLS
LESSON 3: CHEMICAL COMPOUNDS IN CELLS
ELEMENTS AND COMPOUNDS
• An element is a substance that cannot be
broken down any further.
• Carbon, oxygen, etc.
• A compound forms when two or more
elements combine chemically.
• CO2, H2O, etc.
COMPOUNDS IN CELLS
Carbohydrates
• Provide the cell with energy
• Simple carbs are sugars and starches made
from atoms of C, O, and H.
• Complex carbs, like starch and cellulose,
are made in plants.
• Starch = chains of extra sugar
• Cellulose = makes cell wall
COMPOUNDS IN CELLS
Lipids
• Fats, oils, and waxes; cannot mix with water
• Simple lipids are made of C, O, and H, and
are used for energy and structure.
• Contains a molecule of glycerol bonded to
C and H atoms (fatty acids).
COMPOUNDS IN CELLS
Proteins
• Made of amino acids: long chains of
elements (C, O, H, and N mainly).
• Structure and function depends on
composition of amino acids.
• There are many types of proteins:
• Enzymes control chemical reactions
• Others support growth and repair matter
COMPOUNDS IN CELLS
Nucleic Acids
• Hold instructions for maintenance, growth,
and reproduction.
• Made of C, O, H, N, and phosphorous
• Broken into nucleotides
• Deoxyribonucleic acid (DNA) directs a cell’s
function.
• Forms a double helix, like a ladder.
COMPOUNDS IN CELLS
Water
• Helps with chemical reactions.
• Helps cells keep their shape.
• Wilting plants don’t have enough water.
• Helps cells maintain a constant
temperature.
CELLS AND HEREDITY
CHAPTER 1: INTRODUCTION TO CELLS
LESSON 4: THE CELL IN ITS ENVIRONMENT
TRANSPORTING MATERIALS
• Cell membrane controls what goes in and
out because it is selectively permeable:
some substance can cross the membrane
while others cannot.
PASSIVE TRANSPORT
• The movement of dissolved materials across
a cell membrane without using energy.
DIFFUSION
• The process by which molecules spread out,
moving from an area with many of them to
an area with fewer of them.
• Helps cells maintain conditions necessary for
life
OSMOSIS
• The diffusion of water through a membrane.
• If the concentration is higher outside of the
cell, water moves in; if the concentration is
higher inside of the cell, water moves out.
• You can easily see osmosis through plants.
FACILITATED DIFFUSION
• Proteins form pathways for the sugars to
pass through the membrane.
ACTIVE TRANSPORT
• The movement of materials across a
membrane that uses cellular energy.
• Proteins are used to “pick up” materials and
carry them across the membrane.
• Ca, K, and Na
ENDO- AND EXO• Endocytosis: cell membrane changes shape
to engulf the particle.
• Large molecules enter the cell.
• Exocytosis: cell membrane forms an
opening to the outside and forces the
molecule out.
• Large molecules exit the cell.