Transcript sugar - Teacher Pages

Ch. 6.4 Life substances
Objectives:
Classify the variety of organic compounds.
Describe how polymers are formed and broken
down in organisms.
Compare the chemical structures of carbohydrates,
lipids, proteins, and nucleic acids, and relate their
importance to living things.
Identify the effects of enzymes.
The Chemistry of Life
What are living
creatures made
of?
Why do we have
to eat?
2006-2007
Molecules of Life


Put C, H, O, N together in different
ways to build living organisms
What are bodies made of?

carbohydrates




sugars & starches
proteins
fats (lipids)
nucleic acids

DNA, RNA
Why do we eat?

We eat to take in more of these
chemicals

Food for building materials
to make more of us (cells)
 for growth
 for repair


Food to make energy
calories
 to make ATP

ATP
What do we need to eat?

Foods to give you more building
blocks & more energy








for building & running bodies
carbohydrates
proteins
fats
nucleic acids
vitamins
minerals, salts
water
Don’t forget water

Water


65% of your body is H2O
water is inorganic


doesn’t contain carbon
Rest of you is made of carbon molecules

organic molecules
carbohydrates
 proteins
 fats
 nucleic acids

The Role of Carbon in Organisms




Organic compounds
contain carbon
A carbon atom has four
electrons available for
bonding in its outer
energy level. In order
to become stable, a
carbon atom forms four
covalent bonds that fill
its outer energy level.
Carbon compounds vary
greatly in size.
When carbon atoms
bond to each other, they
can form straight chains,
branched chains, or
rings.
How do we make these
molecules?
We build them!
Building large molecules of life

Chain together smaller molecules


building block molecules = monomers
Big molecules built from little molecules

polymers
Building large organic molecules

Small molecules = building blocks

Bond them together = polymers
Making and Breaking of POLYMERS

Cells link monomers to form polymers by
dehydration synthesis (building up)
Short polymer
Unlinked monomer
Removal
of
water
molecule
Longer polymer
Building important polymers
Carbohydrates = built from sugars
sugar – sugar – sugar – sugar – sugar – suga
Proteins = built from amino acids
amino amino amino amino amino amino
acid – acid – acid – acid – acid – acid
Nucleic acids (DNA) = built from nucleotides
nucleotide – nucleotide – nucleotide –
nucleotide
How to build large molecules

Dehydration Synthesis


building bigger molecules
from smaller molecules
building cells & bodies
repair
 growth
 reproduction

+
ATP
Example of synthesis
amino acids
protein
 Proteins are synthesized by bonding amino
acids
amino acids = building block
protein = polymer
How to take large molecules apart

Hydrolysis (Digestion)


taking big molecules apart
getting raw materials


for synthesis & growth
making energy (ATP)

for synthesis, growth & everyday functions
+
ATP
Making and Breaking of POLYMERS

Polymers are broken down to monomers
by the reverse process, hydrolysis
(hydro ~ add water; lysis ~ to split)
Addition of
water molecule
Example of digestion
ATP
ATP
ATP
starch
ATP
ATP
ATP
glucose
ATP

Starch is digested to glucose
1. CARBOHYDRATES

composed of carbon, hydrogen, and
oxygen with a ratio of about two
hydrogen atoms and one oxygen atom for
every carbon atom.
Carbohydrates

Building block molecules = sugars
sugar - sugar - sugar - sugar - sugar
sugar sugar sugar sugar sugar sugar sugar sugar
Carbohydrates

Function:

quick energy

energy storage

structure


glucose
C6H12O6
cell wall in plants
Examples

sugars

starches

cellulose (cell wall)
sucrose
starch
Building carbohydrates
 Synthesis
1 sugar =
monosaccharide
|
glucose
|
glucose
mono = one
saccharide = sugar
di = two
Regents Biology
2 sugars =
disaccharide
|
maltose
Building carbohydrates
 Synthesis
1 sugar =
monosaccharide
|
glucose
|
fructose
How sweet
it is!
Regents Biology
2 sugars =
disaccharide
|
sucrose
(table sugar)
BIG carbohydrates
 Polysaccharides

large carbohydrates
 starch
 energy storage in plants

potatoes
 glycogen
 energy storage in animals
poly = many

in liver & muscles
 cellulose
 structure in plants

cell walls
 chitin
 structure in arthropods & fungi
Regents Biology

exoskeleton
Building BIG carbohydrates
polysaccharide
glucose + glucose + glucose…
=
starch
(plant)
energy
storage
glycogen
(animal)
Regents Biology
Digesting starch vs. cellulose
starch
easy to
digest
cellulose
hard to
digest
Regents Biology
enzyme
enzyme
Cellulose
 Cell walls in plants
herbivores can digest cellulose well
 most carnivores cannot digest cellulose

 that’s why they
eat meat
to get their energy
& nutrients
 cellulose = roughage
 stays undigested
 keeps material
moving in your
intestines
Regents Biology
Lipids
composed largely of
carbon and hydrogen
They are not true
polymers
They are grouped
together
because they do not
mix
with water
(Nonpolar)
(ie. fats, oils,
waxes)
Lipids
 Examples
 fats
 oils
 waxes
 Steroid
 sex
hormones
hormones

testosterone (male)

estrogen (female)
Lipids

Function:

energy storage
very concentrated
 twice the energy as carbohydrates!




cell membrane
cushions organs
insulates body

think whale blubber!
Structure of Fat
not a chain (polymer) = just a “big fat molecule”
Saturated fats

Most animal fats


solid at room
temperature
Limit the amount
in your diet


contributes to
heart disease
deposits in arteries
2003-2004
Lipids include fats,


Fats are lipids whose main function is long term
energy storage
Other functions:


Insulation in higher vertebrates
“shock absorber” for internal organs
Fatty acid
Fatty acid
Saturated & Unsaturated fats

fatty acids of
unsaturated fats
(plant oils) contain
double bonds


These prevent them
from solidifying at
room temperature
Saturated fats (lard)
lack double bonds

They are solid at
room temperature
Saturated fats

Most animal fats


solid at room
temperature
Limit the amount
in your diet


contributes to
heart disease
deposits in arteries
2003-2004
Unsaturated fats

Plant, vegetable & fish fats

liquid at room
temperature


the fat molecules
don’t stack tightly
together
Better choice in your
diet
2003-2004
Saturated vs. unsaturated
saturated
unsaturated
Other lipids in biology

Cholesterol


good molecule in cell membranes
make hormones from it


including sex hormones
but too much cholesterol in blood may
lead to heart disease
2003-2004
Other lipids in biology

Cell membranes are made out of lipids


phospholipids
heads are on the outside touching water


tails are on inside away from water


“like” water
“scared” of water
forms a barrier
between the cell
& the outside
2003-2004