Download Unit 2: Basic Biological Principles - kromko

•Explain the characteristics common to all organisms.
•Compare the structure and function of prokaryotic and eukaryotic cells.
•Describe and interpret relationships between structure and function at
various levels of biological organization (ie., organelles, cells, tissues, organs,
organ systems, and multicellular organisms).
What is Biology????
 Biology is the study of all forms of life. There are
many branches of biology which study more specific
organisms or biological functions. For example…
 Botany  study of plants
 Zoology  study of animals
 Microbiology  study of microorganisms
(bacteria/protists)
Can you think of any branches of biology?
What type of living things exist?
 Biodiversity = the variety of life OR different types of
living things
 Biodiversity generally increases from the poles to the equator.
 Biodiversity is greater in areas with consistently warm
temperatures.
 What are the different types of living things?
 Plants
 Animals
 Fungi
 Protists
 Bacteria
Biodiversity
is greater
closer to the
equator.
Where do all organisms live?
 All living things can be found in the BIOSPHERE.
 The biosphere includes all living things and all the
places they are found. The biosphere includes all
organisms found in:
 Land (terrestrial) environments
 Water (aquatic) environments
 Atmosphere
 Can you name organisms that are
found in each part of the biosphere?
biosphere = everywhere life exists
What do you call specific types of
organisms?
 A species is one particular type of living thing.
 Members of a species can interbreed to reproduce.
 There are about 2 million different living species that have been
identified = a lot of biodiversity!!
 Where are most species located???? Are we still discovering new
species???
What does it mean to be alive?
 An organism must contain ALL of the following
characteristics to be considered “living”!
 Made of cells (one or many)
 Obtains energy (to fuel metabolism = all processes that
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


break down substances and build new substances)
Reproduces and passes on DNA to offspring
Grows and develops
Exhibits homeostasis (constant internal conditions)
Responds to environment and/or stimuli
Adapts and evolves (DNA changes over many
generations)
Cell Theory
 The Cell theory has three principles:
1. All organisms are made of cells.
2. All existing cells are produced by other living cells.
3. The cell is the most basic (smallest) unit of life.
What do ALL cells have in common?
Cells are the smallest, most basic unit of life. There
are two types of cells that make up all living
things…eukaryotic cells and prokaryotic cells.
All cells have common components:
 Cytoplasm
 DNA (Genetic material)
 Plasma (cell) membrane
 Ribosomes
Prokaryotic vs. Eukaryotic Cells
Eukaryotic Cells
Prokaryotic Cells
•
•
•
•
•
NO nucleus
NO membrane enclosed organelles
DNA floating in cytoplasm
extremely small microscopic size
ex. bacteria
•
•
•
•
•
nucleus
membrane enclosed organelles
DNA in the nucleus
small microscopic size
ex. plants, animals, protists, fungi
Name That Cell
Endosymbiosis
 A theory that early eukaryotic cells were formed from
simpler prokaryotes.
 Some organelles, such as mitochondria and chloroplasts,
are believed to have once been prokaryotes that have
evolved to now exist inside eukaryotes.
Cell Organelles
 Cell organelles are tiny structures located inside cells that carry out
specific functions.
 Are cell organelles alive? NO
 What are cell organelles made from? Biological Macromolecules
 Carbohydrates
 Proteins
 Lipids
 Nucleic Acids
Cytoskeleton
• A network of fibers that provides internal structure and support for a cell.
• There are three main types of fibers which form the cytoskeleton.
These fibers are made of proteins. The three types of fibers are:
• Microtubules – long hollow tubes that give a cell its shape
• Intermediate filaments – small fibers that give a cell its strength
• Microfilaments – tiny threads that allow a cell to move and divide
Cell membrane
• Also known as the plasma membrane
• Made of a double layer of phospholipids with proteins
embedded to assist with the transportation of molecules
• Forms a boundary between the cytoplasm and the outside
of a cell and controls what enters and exits the cell
Cytoplasm
• Jelly-like substance inside a cell that contains the cell
organelles. It is made mostly of water and building
blocks like amino acids, nucleotides and simple sugars.
Nucleus
• Stores and protects the genetic information, or DNA, of a cell.
• DNA is located in chromosomes inside the nucleus.
• Is surrounded by a nuclear envelope, or nuclear membrane, that
contains pores that allow molecules to travel in and out of the
nucleus.
• Contains the nucleolus which produces ribosomes for the cell.
Endoplasmic reticulum (ER)
• The Endoplasmic Reticulum (ER) is a network of thin folded
membranes that assists in the processing and transportation of
proteins and lipids.
• Rough ER – Produces, processes and transports proteins (roughness is the
attached ribosomes)
• Smooth ER – Processes and transports lipids
Ribosomes
• The site of protein synthesis (production).
• Ribosomes are made in the nucleolus and can be found floating
freely in the cytoplasm or attached to the Rough ER.
• Ribosomes are responsible for linking amino acids together to
form proteins.
Golgi Apparatus (Golgi Bodies, Golgi Complex)
• Closely layered stacks of membrane-enclosed spaces.
• The spaces within the Golgi apparatus are where
proteins are modified, sorted and packaged.
Vesicles
• Small membrane-bound sacs that isolate and transport
specific molecules (such as proteins and lipids).
Mitochondria
• Supplies energy for the cell in the form of ATP.
• It is the location inside a cell where cellular respiration
(conversion of food to energy) occurs.
• Mitochondria have their own ribosomes and DNA, which make them
a unique organelle (they were once believed to be prokaryotes).
Vacuole
• Fluid-filled sac used
for the storage of
water, food molecules
and enzymes.
• Animal cells contain
multiple small vacuoles
and plant cells contain
one large central vacuole
which helps support the
cell.
Lysosomes
• Organelle that contains enzymes that break down damaged or
worn-out cell parts, breakdown large molecules, and protect cells
from invading bacteria and viruses.
• They are found in large numbers in animal cells.
Centrioles
• Cylinder-shaped organelles made of short microtubules
arranged in a circle. The centrioles are perpendicular
to each other and divide DNA during cell division.
• Centrioles also organize microtubules to form cilia and
flagella (structures used for movement).
• Most commonly associated with animal cells.
Chloroplasts
• Organelles that contain
an outer membrane, as
well as an inner membrane
that contains stacks of
disc-shaped sacs called
thylakoids. The thylakoids
contain chlorophyll and
perform photosynthesis.
Cell Wall
• A rigid layer found in plant cells that
provides protection, support and
shape to the cell.
• In plants and algae the cell wall is
made of cellulose
(polysaccharide….a.k.a. carbohydrate).
• In fungi the cell wall is made of
chitin.
Plant Cell
 Large, central vacuole
 Chloroplasts
 Rigid cell wall outside
of cell membrane
Animal Cell
 No large, central vacuole
 No chloroplasts
 No rigid cell wall
•Describe and interpret relationships between structure and function at
various levels of biological organization (ie. Organelles, cells, tissues, organs,
organ systems, etc..)
Cell Differentiation
 Although all somatic cells contain
the same DNA they may perform
different functions in an organism.
This is due to a process called cell
differentiation, in which a cell will
develop into its mature form based
on the DNA (genes) that is expressed
(read).
 Cells that perform similar functions
are called tissues.
 Tissues that work together to
perform specific functions are called
organs.
 Organs that work together to
perform specific functions form an
organ system.
Organelles  Cells  Tissues  Organs
 Organ Systems  Organisms