Transcript Structures and Functions of Living things

Structures and Functions of
Living things
Chapter 1 lesson 1
Cell Theory
• In Latin, cells means “small compartments”
• In the late 1800’s scientists developed a threepart theory about cells.
The first part of the theory
• Cells are the
of all living things
– All living things are made up of cells.
The second part of the theory
• All life processes take place in cells
– The energy in food is released in cells. Growth and
reproduction take place in cells
The third part of the theory
• New cells are produced from existing cells
– Living things begin life as a single cell. This cell
divides into two cells. Each new cell also divides into
two cells. After a certain point, the cells being to
specialize and take on different functions.
– Cell division is what causes you or any other
organism to grow.
Parts of a cell
• Don’t
worry
we
aren’t
going to
learn
about all
of these
parts in
this
lesson…
Organelles and cytoplasm
• Inside both plant and animal cells, there are
types of structures that perform specific
functions. These structures are called
organelles.
• The organelles are surrounded by cytoplasm,
a clear, jellylike substance that holds them in
place.
Cell wall
• The cell wall is a stiff outer layer that
surrounds and protects the cell and gives it
shape
• In this picture, the cell wall is bright blue
Cell membrane
• The cell membrane is a layer that holds the
cell material inside. The membrane controls
what substances enter and leave the cell
Nucleus
• The nucleus is the cell’s control center. It
directs all of the activities that take place
inside the cell.
Chromosomes
• The nucleus contains chromosomes, the
structures that carry an. organism’s genetic
information (DNA). They also control activities
within the cell.
• The nuclear membrane surrounds the nucleus
and holds it together
DNA
• Chromosomes are made up of DNA and
proteins.
• DNA stands for deoxyribonucleic acid. This
chemical provides detailed instructions to the
cell about every function of life. It contains
codes that determine physical characteristics
such as a flower color in plants and hair color
in humans.
Chloroplasts
• The chloroplasts make the plant’s food (sugar)
by the process of photosynthesis. They are
found mostly in the plants’ leaves.
Mitochondria
• Cells also contain bean-shaped organelles called
mitochondria.
• Food and oxygen combine in the mitochondria to
release the food’s energy, carbon dioxide, and
water. This process is known as respiration. The
energy released during respiration enables a
plant or animal to complete all its cell activities.
Vacuole
• Both plants and animal cells have organelles
called vacuoles, which store nutrients and
wastes. In animal cells, vacuoles are very
small. In plants, one large vacuole takes up
most of the cell.
How do plant cells and animal cells
differ?
• * Two structures that plant cells have, that
animal cells do not, are chloroplasts and cell
walls
• * Vacuoles are different in plant and animal
cells because plants have one large vacuoles
and animals may have several smaller
vacuoles.
*Images Provided by Google and AltaVista