Transcript cells final - educ399portfolioedwinawilson

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1665
Robert Hooke looked at a slice of cork under a
compound microscope and discovered the cork was made
up of small “boxes” that he named cells
Cells are the Starting Point of life›
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All living organisms on Earth are divided in pieces called
cells.
Proteins and organelles
Tissues and systems.
Keep an organism alive and successful on Earth.
A main purpose of a cell is to organize. Cells hold a variety
of pieces and each cell has a different set of functions.
Growth and development
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The British physiologists William Bayliss (1860-1924) and Ernest
Starling (1866-1927) discovered secretin in 1902. They used the
term "hormone" (from the Greek word horman, meaning "to
set in motion") to describe the chemical substance they had
discovered that stimulated an organ at a distance from the
chemical's site of origin. Their famous experiment using
anesthetized dogs demonstrated that dilute hydrochloric
acid, mixed with partially digested food, activated a
chemical substance in the duodenum (the upper part of the
small intestine). This activated substance (secretin) was
released into the bloodstream and came into contact with
cells of the pancreas. In the pancreas it stimulated secretion
of digestive juice into the intestine through the pancreatic
duct.
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1914 Edward Kendall isolates thyroxine, the active
hormone of the thyroid gland, and shares the 1950
Nobel Prize with Tadeus Reichstein and Philip
Hench for discoveries relating to the structure and
biological effects of adrenal cortical hormones.
1921 Frederick Banting, Charles Best and John
Macleod discover the hormone insulin that leads to
the first effective treatment for diabetes. Banting
and Macleod win the 1923 Nobel Prize for their
research and share their award with colleagues
Best and James Collipp.
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Known living things are made up of one or more
cells.
All cells arise from pre-existing cells by division.
The cell is the fundamental unit of structure and
function in all living organisms.
The activity of an organism depends on the total
activity of independent cells.
Energy flow (metabolism and biochemistry) occurs
within cells.
Cells contain hereditary information (DNA) which is
passed from cell to cell during cell division.
All cells are basically the same in chemical
composition in organisms of similar species
HORMONES! i.e secretin
 What are hormones?
Hormones are chemical messengers
secreted into blood or extracellular fluid
by one cell that affect the functioning of
other cells.
Most hormones circulate in blood, coming
into contact with essentially all cells.
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The endocrine system is the interacting
group of glands that secrete hormones,
helping to control cells and organs
throughout the body.
 How do cells and organs at different
locations in the body communicate with
each other to maintain the physiology of
healthy living organisms?
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Hormones are "signaling" molecules because they
influence the activity of other cells that may be far
from where the hormone was produced.
For a hormone to affect a target cell, it must
attach to a receptor protein on the target cell
membrane or inside the cell. Hormone binding to a
receptor triggers an intricate set of biochemical
interactions that can affect the target cell in
myriad ways.
For example, hormones can influence cell
metabolism, cell division, electrical activity,
ribonucleic acid (RNA) and protein synthesis, or cell
secretion
The majority of hormones are peptides.
These consist of short sequences of amino
acids ; examples include insulin and growth
hormone.
 The class of hormones called steroids are
synthesised from cholesterol—examples
include male sex steroids such as testosterone
and female sex steroids such as estrogen and
progesterone.
 Hormone production by an endocrine organ
is regulated by complex interactions, called
feedback loops, between the endocrine
organ and its target organs..
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Cells manage to do everything so smoothly in
our bodies. They do so by constantly sending
and monitoring a stream of messages- a lot of
different messages are communicated---instructions, queries, corrections, requests for
assistance, updates, notices of divide or expire.
The main means of doing this is through
hormones found in the endocrine system.
The discovery of secretin led to the further
investigation of the function of hormones in our
body which further allowed scientists to
discover that they help our bodies function
smoothly.