Transcript MP2 Powerpoint

MP2 POWERPOINT
Living Environment
2
Period 4 12/07/12
1. Attendance
2. Test today
1. No electronics during or after the test.
2. Sit facing front.
3. No talking or disturbing others.
4. Raise your hand if you have a question
1.
Although – please don’t ask me to explain how to do a question!
Homeostasis a.k.a.
Dynamic (ENERGY!) Equilibrium (BALANCE!)
-internal (inside)
-external (outside)
-Homeostasis
-temperature
-salt and water
-glucose (simple sugar; C H O )
-temperature
-98.6°F
-positive feedback=labor contractions!
6
12
6
“OFF”
“ON”
hair up,
vasoconstriction,
shivering
heat saved,
heat made,
blood warms
“OFF”
“ON”
hair down,
vasodilation,
sweating
heat lost,
blood cools
• insulin
• lowers
• carbohydrates
• glucose
• cellular respiration
What is hyperglycemia?
Hyperglycemia (hi"per-gli-SE'me-ah) is an increase in
plasma glucose (blood sugar). It can turn into a complex
medical condition -- diabetic ketoacidosis (ke"to-as"idO'sis) and coma -- if it's not treated on time and
adequately. Hyperglycemia is usually the first sign of
diabetes mellitus. Symptoms of hyperglycemia are
• polyuria (pol"e-YUR'e-ah) (excess urine)
• polydipsia (pol"e-DIP'se-ah) (thirst)
• polyphagia (pol"e-FA'je-ah) (excessive hunger)
What is hypoglycemia?
Hypoglycemia (hi"po-gli-SE'me-ah) is a low level of
plasma glucose (blood sugar). It's a dangerous condition
because glucose is the major source of energy for the
brain. Lack of glucose, like lack of oxygen, produces brain
damage or even death if the deficit is prolonged.
Hypoglycemia starts to cause these symptoms: sweating,
tremors, anxiety, hunger, dizziness, headache, cloudy
vision, confusion, abnormal behavior convulsions, loss of
consciousness.
“ON”
(insulin
released)
sugar uptake into
cells, stored as
glycogen
“OFF”
(insulin
stopped)
normal blood sugar
“OFF”
“ON”
less ADH
secreted,
less urine
water
levels
normal
11
Enzymes: Who needs them?
• You do if you like detergents, bread,
baby food, beer, fruit juice, cheese,
candy, rubber, paper, or film because
enzymes are needed to make these
products!
• You do because living things can’t live
without them and you, my friend, are a
living thing.
12
A tasty and delicious example of
an enzyme at work…
• Complex carbohydrates like
A carbohydrate made of
glucose subunits!
Glucose, a simple sugar.
salivary amylase
starch and glycogen are broken
down into the simple sugar
a.k.a. monosaccharide glucose
in your mouth with the help of
the enzyme salivary amylase. I
guess spit’s fantastic!
13
A not-so tasty and delicious
example of an enzyme at work…
• The enzyme lactase, with the
help of water, breaks (digests)
the disaccharide lactose down
into 2 monosaccharides─
galactose and glucose. Many
adults, however, don’t make
enough lactase so ingesting
dairy causes symptoms like
painful gas and diarrhea. Uh-oh!
14
Enzymes are everywhere!
even in a bug’s butt
• luciferin + ATP
luciferase
oxyluciferin + AMP + light
• The above chemical equation represents a biochemical
process that occurs in the abdomen of the firefly called
bioluminescence. Without the enzyme luciferase to
push the chemical reaction along, the insect would not
glow and, therefore, would not be able to attract a
mate.
Photinus greeni finds a mate thanks,
in part, to the enzyme luciferase!
15
How do enzymes
keep us alive?
• An enzyme is a protein that
catalyzes,
or speeds up, a chemical reaction. Without
enzymes, many of life’s vital biochemical
processes would happen too slowly or not at
all! Think about a little kid on a swing. Without
a push, they aren’t going to get going. With a
few pushes, though, that kid can swing on
their own. The enzyme is what gives the
biochemical process the push it needs to get
going.
16
Enzymes are catalysts.
• Enzymes are biological catalysts. A catalyst makes
a chemical reaction go faster but is not changed or
used up by the reaction. The reason the enzyme’s
name is written above the arrow in a chemical
equation is because it is the only molecule not
changed during the chemical reaction a.k.a.
biochemical process.
• This means that the same enzyme can be used over
and over again which saves the body energy
because it doesn’t have to make new enzymes each
time. Way to work smarter, not harder, body!
17
What’s a lock got
to do with it?
• You have 1000s of
enzymes in your cells and
each one speeds up a
different chemical
reaction a.k.a.
biochemical process.
• An enzyme’s shape
determines what
substrate it acts upon.
This is called specificity
and is illustrated by the
lock-and-key model.
18
Enzymes: They Look a Hot Mess
But They’re a Specific Shape
• Here is an image of the
restriction endonuclease
enzyme EcoRI which digests
DNA.
• Here is an image of the enzyme
lactase which digests milk
sugar.
19
So what might an enzyme do during a
chemical reaction?
• An enzyme grabs a substrate (the molecule that the
enzyme changes) and breaks it apart.
• The active site is where enzyme and substrate connect.
• In this example, the name of the reactant is sucrose.
The names of the products are glucose and fructose.
• This is a breakdown a.k.a. digestion reaction and it
releases energy when bonds are broken!
20
Are digestion reactions the only
type of reaction?
• No! There are also
synthesis reactions
where an enzyme
makes a big molecule
out of 2 smaller ones.
This uses energy!
Here’s a synthesis reaction taking place in your blood that
happens 10 million times faster thanks to the enzyme:
CO2 + H2O
carbonic anhydrase
21
How do enzymes speed up reaction rates
and what affects them?
• Enzymes work by lowering the activation
energy─ the amount of energy needed to push
a chemical reaction forward.
 Each enzyme works best at a certain
temperature, pH (acidic, neutral, or basic), and
concentration (how much enzyme or substrate
is around). Your body’s enzymes work best at
normal body temperature and a neutral pH
except for enzymes in the stomach and vagina
which have adapted to an acidic environment.
22
Do enzymes always work?
• Sometimes high temperature or extreme pH
(strong acids and bases) may affect the shape
of an enzyme.
• This effect is called denaturation and can
make the enzyme less effective and possibly
useless.
• Just as a melted house key won’t open your
door, a denatured enzyme won’t work on its
substrate! Good luck maintaining homeostasis
if that happens!
It just may be the
dun-dun-schnipple!
FOOD
1. Provides energy for all of the body’s functions, from the
beating of the heart & the elimination of wastes to the
transmission of electrical & chemical signals in the nervous
system. Food is the fuel that contains energy from the sun,
originally captured & stored by green plants, then passed
along to fruits, seeds, & animals. Humans eat these foods
& burn the fuel they contain to release the stored solar
energy. As long as we live, we have to eat and eat often!
Text from: Eating Well for Optimum
Health Andrew Weil, MD
2. Food provides the building blocks of our bodies. In the same
way that you can’t build a lego castle without lego pieces, you can’t
build the parts of your body without certain nutrients.
The food we eat contains nutrients. Some of these we disassemble
and then reassemble for parts we need. (Like breaking down the lego
castle to build a lego ship instead.)
Some nutrients are essential because we can’t manufacture these on
our own.
Macromolecules are these nutrients.Macromolecules come in 4
types. All macromolecules are organic which means they are
produced and made by living things.
Carbohydrates
Lipids
Proteins
Nucleic acids
CARBOHYDRATES
All carbs are made up of only 3
elements: Carbon, hydrogen, & oxygen.
All carbs look like this in their simplest form. By
the way, this is called a simple sugar or
monosaccharide.
mono = one saccharide = sugar
But remember I said that you can use these
guys as building blocks. Well if you put two
of them together you get this. It’s called a
disaccharide. Di = two
And if you string a bunch of monosaccharides together you
get a polysaccharide. They look like this.
Luckily they have the same general shape (hexagonal) and they
are all carbohydrates .
WHY ARE CARBOHYDRATES IMPORTANT?
They are the body’s preferred choice of
energy .
Just like your favorite shirt, you could wear the
other shirt, but this one fits over your head without
tugging.
WHAT FOODS CONTAIN CARBOHYDRATES?
Let’s review carbohydrates.
Why do you need to eat
them?
What foods contain carbs?
List the 3 elements that are
contained in carbohydrates.
Which of the following is a
polysaccharide?
LIPIDS
Lipids contain 3 elements; carbon,
hydrogen and oxygen.Sounds familiar
right!
Fats are triglycerides which are solid at room
temperature.
Oils are liquid at room temperature.
Why are lipids important to our bodies?
1. Storage of energy. This way if
you run low on carbs…..
2. Thermal insulation.
3. Mechanical protection. Example surrounding delicate
organs such as the heart.
4. Waterproofing. Like the wax in your ears.
Some fats are called phospholipids. They
look like this.
Basically , the difference is that
instead of 3 fatty acids and one
glycerol, they have 2 fatty acids
and a glycerol.
The also have an end that
loves to be in water and a
side that repels water.
Two layers together is a perfect
way to surround a cell or a cell
part!
Also, by the way, some hormones are lipids.
WHAT CAN YOU EAT TO MAKE SURE YOU
HAVE LIPIDS?
Butter
Review time.
What 3 elements make up the group called lipids?
Which of these are a lipid? How can you tell?
List 3 ways your body uses lipids.
What foods contain lipids?
PROTEINS
Proteins are composed of 4 elements: carbon, hydrogen,
oxygen and nitrogen. The basic unit is called an amino
acid and it looks like this.
This is a 3-D image of a
protein containing thousands
of amino acids connected
together & folded to make this
distinct shape.
WHY DO YOU NEED TO EAT PROTEINS?
Proteins make up most of the structure of
your body. Actually, by weight, you are
mostly water with proteins in second place.
These are muscle cells.
This is someone with
big muscles.
Hair is also made up of protein.
Proteins can be enzymes; these proteins regulate chemical
reactions in your body.
Proteins also form some of the entrances and exits
through the cell.
WHICH FOODS PROVIDE PROTEINS IN OUR DIET?
Review again? Of course!!!!
1. Which of the following suspects
is a protein component?
2. List some foods that provide proteins?
3. How does my body use proteins?
NUCLEIC ACIDS
Nucleic acids make up DNA and RNA which are
gigantic molecules that carry your hereditary
information from generation to generation and
are used to make proteins (remember them).
Nucleic acids are made
up of lots of nucleotides
(the smallest units)
strung together. DNA
takes the shape of a
double helix.
We will learn a lot more about
nucleic acids later!!!!
VITAMINS AND MINERALS
Micronutrients are nutrients you need in small amounts.
(That’s why they’re called micro.)
All natural vitamins are organic food substances found only in
living things. With few exceptions, our bodies can’t manufacture
them. Many enzymes depend on vitamins to work properly.
Minerals are inorganic substances such as calcium, iron, and salt
that we need for such basic functions as muscles and nerves
firing.
WATER makes up more than half the weight of the human body.
Without water, humans would die in a few days. All the cell and organ
functions depend on water for functioning. It serves as a lubricant and
forms the base for saliva and the fluids that surround the joints. It
regulates the body temperature, as the cooling & heating are
distributed through perspiration. Water helps to alleviate constipation
by moving food through in the intestinal tract & thereby eliminate
waste.
Dehydration is a lack of adequate body fluids for the body to carry
on normal body functions. Fluid loss of 5% are considered mild, 10%
moderate and up to 15% severe. Severe dehydration can result in
cardiovascular collapse and death if not treated quickly.
Symptoms: sunken eyes, dry or sticky mucus membranes in the
mouth, skin lacks normal elasticity, decreased urination, decreased
tears.
WHAT HAPPENS WHEN
YOU DON’T GET THE
NUTRIENTS YOU NEED?
Kwashiorkor
Meeting energy requirements is basic to
survival A diet with excessive
nonprotein calories from starch or sugar,
but deficient in total protein and essential
amino acids, results eventually in
kwashiorkor.
Kwashiorkor is characterized by
generalized edema, "flaky paint'
dermatosis, thinning and discolouration
of the hair, enlarged fatty liver, and
apathy in addition to retarded growth.
Anorexia nervosa is an eating disorder associated
with a distorted body image. Inadequate calorie
intake results in severe weight loss.
Symptoms: Weight loss of
25% or more, cold
intolerance, constipation
menstruation absent, skeletal
muscle atrophy, low blood
pressure, dental cavities,
increased susceptibility to
infection, blotchy or yellow
skin, dry hair, hair loss and
sometimes death.
Cheese pizza diet causes scurvy in 5-year-old
July 17, 2000
NEW YORK (Reuters Health) - When it was discovered
that sailors away at sea could stop their gums from
bleeding by sucking on a lime, one of the first links
between disease--in this case, a vitamin C deficiency-and diet became apparent. But a recent report illustrates
that even modern-day children anchored at home are
vulnerable to scurvy--a vitamin C deficiency that causes
bleeding gums, loose teeth, muscle degeneration and
weakness.
In one case, a 5-year-old boy ate nothing but Pop-Tarts,
cheese pizza, biscuits and water for 5 months, according
to a report in the July issue of the Archives of Pediatrics
and Adolescent Medicine. He refused fruits, vegetables,
juices and vitamins. The result? A case of scurvy--a
disease seldom seen in developed countries today.
While the boy was playful, alert and appeared to be
growing normally, he developed a limp and was
diagnosed with anemia. His gums became swollen and
he developed small, purple spots on his skin.
Eventually, the pain was so severe he was unable to get
out of bed or walk without assistance.
After ruling out leukemia or other ailments, the doctors
diagnosed the youngster with a severe vitamin C
deficiency, most likely caused by his unusual diet.
The doctors gave the boy vitamin C, which improved
his pain and symptoms within a week.
TIME FOR THE BIG REVIEW!
`
IDENTIFY EACH OF THE FOLLOWING
MACROMOLECULES
HOW ARE EACH OF THESE MOLECULES USED IN
YOUR BODY?
CARBOHYDRATES
PROTEINS LIPIDS
WHICH ELEMENTS MAKE UP THE CHEMICAL
FORMULA OF THE GROUPS LISTED ABOVE?
RESPIRATION
1
2
THE CONCEPT OF ‘RESPIRATION’ IS
CENTRAL TO ALL LIVING PROCESSES
It is worth while studying this presentation
thoroughly because it is essential for an
understanding of all the activities of living cells
and organisms
3
All living cells are made up of chemical substances
The processes of living involve reactions between the
substances
A reaction is an event which produces a change in a
substance
For example, a reaction between carbon and oxygen
(such as burning coal in air) changes the carbon in
the coal, and oxygen in the air into carbon dioxide
This reaction can be represented by the equation
C
carbon
+
O2
CO2
oxygen
carbon dioxide
4
plus
an atom of carbon
c
C
a molecule of oxygen
O2
o
o
combine to form a molecule of carbon dioxide
CO2
5
The reaction between carbon and
oxygen also releases energy in the
form of heat and light (flames)
Living organisms get their energy
from reactions like this (but not
reactions which are violent enough
to produce flames)
6
CO2
energy release
source of carbon
source of carbon
oxygen
7
One of the energy-producing reactions is called
respiration
(Respiration is not the same thing as breathing)
The chemical reactions of respiration take place
in all living cells
The reaction takes place between oxygen and a
substance which contains carbon. The reaction
produces carbon dioxide and water, and releases
energy
8
The carbon-containing substances come from FOOD
The oxygen comes from the AIR (or water)
The energy is used to drive other chemical reactions
taking place in cells
One example of this is the release of energy in muscle
cells to make them contract and produce movement
9
One example of an energy-producing reaction in cells is
the breakdown of sugar when it combines with oxygen
This can be represented by the equation
C6H12O6 + 6O2
sugar
(glucose)
oxygen
6CO2 + 6H2O +
carbon
dioxide
energy
water
This means that one molecule of sugar reacts with six
molecules of oxygen to produce six molecules of
carbon dioxide and six molecules of water.
Energy is released during this process
10
Some examples of the use
of energy in organisms
muscle
contraction
Respiration
supplies
the energy for
germination
chemical changes in cells
cell division
11
Energy use in muscle contraction
shoulder blade
The blood stream brings food
and oxygen to the muscle
cells. Respiration occurs in
the cells and releases energy
which……
upper arm
bone
lower arm bones
12
…….makes the muscle contract
and pull the lower
arm up
13
food store
embryo
shoot
shoot
embryo
root
(a)
(b)
(a) is a section cut through the
length of a maize seedling. Areas
of rapid respiration are stained pink.
(b) and (c) are drawings of the seed
and the seedling that grows from it.
Can you suggest reasons why
respiration should be so rapid in the
stained regions?
(c)
root
root
14
Answer
The most intensely stained areas are in the root tip and the
shoot tip. These are regions where very rapid cell division is
taking place to produce growth. Making new cells and new
cytoplasm takes a great deal of energy.
You might also have noticed that, in the root, there are two
faint streaks of pink. These occur in the conducting tissue of
the seedling. Energy is needed to transport food from the
food store to the growing region.
One example of respiration in ourselves
2. The lungs absorb oxygen
from the air
2.The stomach and
intestine digest food.
One of the products
is glucose
4 RESPIRATION
Glucose and
oxygen react to
produce energy for
muscle contraction
15
1. Air taken in
1.Food taken in
3.The blood stream
carries glucose and
oxygen to the muscles
5 Carbon dioxide
is carried to the lungs
by the blood
23
Anaerobic Respiration
24
The process of respiration described so far has been defined
as the release of energy when foodstuffs such as glucose
react with oxygen to produce carbon dioxide and water.
This form of respiration, which needs oxygen, is called
aerobic respiration.
There is another form of respiration which does not need
oxygen and is called anaerobic respiration.
In anaerobic respiration, glucose is still broken down to
carbon dioxide with the release of energy, but without the
involvement of oxygen
The glucose is not completely broken down to CO2 and H2O
but to CO2 and alcohol (ethanol).
25
Anaerobic respiration can be represented by the
equation
C6H12O6
glucose
energy
2C2H5OH
+
2CO2
alcohol
The energy released by anaerobic respiration is considerably
less than the energy from aerobic respiration.
Anaerobic respiration takes place at some stage in the cells
of most living organisms.
For example, our own muscles resort to anaerobic
respiration when oxygen is not delivered to them fast
enough.
26
Anaerobic respiration is widely used by many micro-organisms
such as bacteria and yeasts.
Bacteria and yeasts are microscopic single-celled organisms.
Bacteria are to be found everywhere, in or on organisms,
in water, air and soil
Yeasts are usually found in close association with
vegetable matter such as fruit
27
Bacteria
cell wall
there are many
species of bacteria
and they have different
shapes and sizes
nucleus
cytoplasm
0.002mm
a single bacterium
28
Aerobic and anaerobic bacteria
Bacteria which need oxygen in order to respire are called
aerobic bacteria.
Aerobic bacteria are likely to be found in the air, water
and soil where oxygen is available
Bacteria which can respire without needing oxygen are
called anaerobic bacteria
Anaerobic bacteria are to be found in situations where
oxygen is lacking, such as in stagnant water, waterlogged
soils or the intestines of animals
30
Fermentation
One form of anaerobic respiration in bacteria and yeasts
is called fermentation.
During fermentation, sugar is broken down to alcohol and
carbon dioxide
The reaction described in slide 25 is an example
of fermentation
Fermentation is involved in brewing and wine-making
29
Yeasts
cell wall
cytoplasm
nucleus
0.005mm
vacuole
Yeast cells dividing
single yeast cell
Baking
In baking, yeast is added to a mixture of flour and water,
made into the form of a dough
The yeast first changes the flour starch into sugar and then
ferments the sugar into alcohol and CO2
The CO2 forms bubbles in the dough which cause it to
expand (‘rise’)
When the dough is baked, the heat evaporates the
alcohol but makes the trapped bubbles expand giving the
bread a ‘light’ texture
35
Dough rising
The yeast is mixed
with the dough
After 1 hour in a warm
place the dough has
risen as a result of the
carbon dioxide
produced by the yeast
36
37
The ‘holes’ in the
bread are made by
the carbon dioxide
bubbles.
This gives the
bread a ‘light’
texture
1. What does the
tubing represent?
Cell
membrane
2. What is inside
the tubing?
Starch & glucose
3. What did
we add to
make the
liquid outside
the “cell”
amber
colored?
Starch indicator
(iodine aka
Lugol’s
Solution)
4. Why does
the inside of
the “cell” turn
purple or
black?
High s.i.conc.
Low s.i. conc.
Starch indicator
diffused into the
tubing
5. How do we
know that
starch did not
move from the
inside to the
outside?
No color change
outside. If there
was starch in the
beaker water, it
would be purple!
6. How can
we find out if
glucose
moved into
the beaker?
?
Glucose
(high
conc.)
Do a glucose
indicator test
using the fluid
in the beaker
7. After
placing 10
drops of the
amber
solution into a
test tube,
what do we
add to it?
Glucose indicator aka Benedict’s
Solution
8. After adding
the glucose
indicator
solution (blue)
what do we do
with the test
tube?
Heat it
9. If there is
glucose in the
solution, what
will happen to
the blue color
after heating
the tube for 2
minutes?
The color changes
10. The blue
color changed
to orange. This
means that
what substance
is in the test
tube?
Glucose
starch
glucose
C6H12O6
11. Glucose indicator solution was
added to these test tubes, and
then the tubes were heated.
Which will change color?
What
is this??
(hint:
“plants”)
Were you right?