Cell Processes

Cell Processes

From TransportTo

Reproduction

Homeostasis• This maintenance of a stable internal environment

by an organism is called homeostasis.  • living things, from the cells and their organelles

to the organ systems of complex organisms interact to maintain a balanced internal environment .   Organisms have many control mechanisms to detect internal and external changes and to make changes.   

• Failure to respond effectively can result in disease or death. 

• Examples: humans sweat when they are hot are shiver when they are cold to maintain a body temperature around 98.6

Transport of materials go across the Cell Membranes

• Cell membranes have pores (holes) in ita.Selectively permeable: Allows some

molecules in and keeps other molecules outb.The structure helps it be selective!

Pores

PASSIVE TRANSPORT• The movement of substances

through the cell membrane without the input of energy.

• Diffusion• Osmosis• Facilitated diffusion

Cells at Work Passive TransportDiffusion- the movement of molecules from an area of Greater concentration toan area of lesser concentration.http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

Example: ink in water spreads out.Example: perfume in air spreads out.Example: food cooking odors spreading through the house

OsmosisPassive Transportthe movement of water

molecules from an area of high concentration to an area of low concentration.

http://www.stephsnature.com/lifescience/osmosisanimations.htm

FACILITATED DIFFUSIONPassive Transport-Is when materials move through the cell membrane through protein gates or channels without energy.-To facilitate means to help. The proteins help the materials move through the membrane.http://www.biology.arizona.edu/cell_bio/problem_sets/membranes/07t.html

Isotonic Environment

• The cell and its environment have the same percentage of dissolved solutes

Hypertonic Environment

• The cell’s environment has a larger percentage of dissolved solutes.

• EXAMPLE: very salty water

Hypotonic Environment

• The cell’s environment has a small percentage of dissolved solutes.

• EXAMPLE: very pure water

Tonic = “Pressure” Water

• Isotonic is the same thing as “iso-osmotic”

• Hypertonic is the same thing as “hyper-osmotic”.

• Hypotonic is the same thing as “hypo-osmotic”.

ACTIVE TRANSPORT

is an energy –requiring process in which transport proteins bind with particles and move them through a cell membrane.

Used when large molecules cannot get through the cell membrane.

Types of Active Transport• Protein Pumps -transport proteins that require

energy to do work• Example: Sodium / Potassium Pumps are

important in nerve responses.

• Endocytosis- the process of taking substances into the cell. Endo means into. Example: white

blood cell eating bacteria.• Exocytosis –releasing substances out

of the cell. Exo means to exit. example where hormones or waste are released from the cell

http://www.phschool.com/atschool/phbio/active_art/active_transport/index.html

EQUILIBRIUM

• OCCURS WHEN MOLECULES FROM ONE SUBSTANCE SPREADS EVENLY THROUGHOUT ANOTHER SUBSTANCE.

• (after equilibrium is met, molecules still move- one molecule in one molecule out

• http://www.stephsnature.com/lifescience/osmosisanimations.htm

3 ways to make energy1. Cellular respirationMitochondria burn fuel to provide our cells with energy. A

chemical reaction called cellular respiration takes place in the mitochondria.

C6H12O6 + 6O2 6CO2 + 6H2O + energyGlucose + oxygen carbon + water + energy dioxide 2. PhotosynthesisThe process where plants make food in the form of

sugar in the chloroplast.6CO2 + 6H2O +light energy C6H12O6 + 6O2 Carbon + water + light energy glucose + oxygendioxide

3. FERMENTATION• Who uses fermentation? SINGLE CELL

ORGANISM THAT ARE ANAEROBIC (WITHOUT OXYGEN) AND HUMAN MUSCLES

• It PROVIDES ENERGY FOR CELLS WITHOUT USING OXYGEN.

• ENERGY RELEASED BY THIS METHOD IS MUCH LOWER THAN DURING CELLULAR RESPIRATION.

• BY PRODUCTS: ARE ALCOHOL AND LATIC ACID as seen when making BREAD using yeast.

Cell Division•Mitosis occurs inBody cells, like skin,Nerves, heart, hair, toes.•Mitosis – the process in which the nucleus divides to form two identical nuclei•Start off with 1 cell and end up with 2 (daughter) cells•Every human cell the reproduces through mitosis has 46 chromosomes

Meiosis• The process of cell division in sexually

reproducing organisms that reduces the number of chromosomes in reproductive cells from diploid to haploid, leading to the production of gametes, sex cells like sperm and eggs, in animals and spores in plants.

• Found in egg and sperm cells• Start off with 1 cell and end up with 4

(daughter) cells• Every human cell (only egg or sperm cell)

that reproduces through meiosis has 23 chromosome (haploid)

When Cells Get TogetherLevels of Organization

Living things have different levels of organization.    The simplest level of organization is that of the cell.  

A group of cells with a similar function is called a tissue.   Groups of tissues working together to

perform a common function are called organs.  An example of this would include the nervous, muscle,

and other tissues which make up the heart.   Groups of organs working together to perform a common

function are referred to as a system or organ system.   The blood vessels, blood, and the heart

are organs which work together to form the circulatory system.   Many different systems function together to allow a complex organism to function.

CellsNerve cells

TissuesNerve tissue Brain

/organ

Organ SystemsNervous system

Organisms

TISSUES VS ORGANSKidney tissue /organs/

organ system

Stomach tissue

/ organ/Organ

system

PLANT CELLS TO ORGANISM

ORGANS IN PLANTS ARE:LEAVES, STEMS, ROOTS

CELL SHAPE RELATED TO FUNCTION• Role of different shapes of animal cells: The

difference in shape of all these cells are significant for their identification.

• Shape of neuron cells helps it to transport signals.

• • Shape of the muscle fibers help in muscle

contraction.

nucleus Myelin sheath

Dendrite