Download cell division. - cis myp science

Body Organization and
Homeostasis
Organization of the Body
Cell Theory
• All living things are made up of cells. (1830s)
• Cells are the smallest working units of all living
things.
• All cells come from preexisting cells through cell
division. (1850s)
Function of Cells
- Carry on the processes that
keep organisms alive.
- Cells also grow and
reproduce
- Cells get rid of waste
products that result from
these activities
Homeostasis
• Homeostasis is the process by which an organism’s
internal environment is kept stable in spite of changes in
the external environment.
• Regulates temperature
• Too warm, you sweat
• Too cold, you shiver
• Stress
Cell Organelles
• cytoskeleton
• centrioles
• peroxisomes
• ribosomes
• nucleolus
• smooth ER and rough ER
Cytoskeleton
The cytoskeleton is a structure that helps cells maintain their
shape and internal organization
Provides mechanical support that enables cells to carry out
essential functions like division and movement.
Made of different types of protein, microtubules and filaments
Highway for
connections
and transportation
Centrioles
A centriole is a small set of
microtubules arranged in a specific
way.
When two centrioles are found next
to each other, they are usually at
right angles.
The centrioles are found in pairs and
move towards the poles (opposite
ends) of the nucleus when it is time
for cell division.
Peroxisomes
Peroxisomes are small, membraneenclosed organelles that contain
enzymes involved in a variety of
metabolic reactions, including
several aspects of energy
metabolism.
Its proteins must be imported.
Are major sites of oxygen
utilization.
Ribosomes
Responsible for production of protein in all living cells.
Function of Proteins
Enzymes are proteins that speed up chemical reactions
in the body. Hormones, like insulin, are proteins that
regulate the activity of cells or organs.
Some proteins transport materials throughout your
body, such as hemoglobin, which is the oxygentransporting protein found in your red blood cells.
Structural proteins provide support in our bodies. For
example, the proteins in our connective tissues such as
collagen and elastin
Nucleolus
Nuclear subdomain that assembles ribosomal subunits.
Smooth ER and Rough ER
• - Smooth ER - no ribosomes, synthesis of lipids and
hormones
• Rough ER – transports PROTEINS to the Golgi
Apparatus