Download Glucose

Unit 3 Major Topics
3.1 Chemical elements of water
3.2 Carbohydrates, lipids, proteins
3.3 DNA structure
3.4 DNA replication
3.5 Transcription & Translation
3.6 Enzymes
3.7 Cell Respiration
3.8 Photosynthesis
3
4,5
16-18
16-18
16-18
8
9
10
3.1
Chemical Elements
&
Water
Essential Elements of Life
• About 25 of the 92 elements are essential to
life
• What make up 96% of living matter?
– Carbon, hydrogen, oxygen, and nitrogen
• Most of the remaining 4% consists of calcium,
phosphorus, potassium, and sulfur
The other 4% of elements
• Sulfur
– All plants need S to grow because S is in all proteins.
– Also, active part of amino acids
• Calcium
– Calcium makes up 1.5% of the average human body
– A balance of CALCIUM is maintained in a healthy animal
– Used for bone production
– Calcium in plants  middle lamella
• Phosphorus
– Major components in nucleotides & ADP & ATP
• Iron
– Hemoglobin carries oxygen via red blood cells throughout the
body.
– Plays a key role in the production of chlorophyll in plants
• Sodium
– Sodium potassium pump (nervous system)
– Most plants do not need it.
Nitrogen deficiency
• WATER?
Iodine deficiency
Resulting from Goiter
Name
(molecular
formula)
Water (H2O)
Electronshell
diagram
Structural
formula
Spacefilling
model
• Electronegativity is an atom’s attraction for the
electrons in a covalent bond
• The more electronegative an atom, the more strongly it
pulls shared electrons toward itself
• In a nonpolar covalent bond, the atoms share the
electron equally
• In a polar covalent bond, one atom is more
electronegative, and the atoms do not share the
electron equally
• The water molecule is a polar covalent molecule
• Polarity allows water molecules to form hydrogen
bonds with each other
• THIS IS CALLED COHESION!
–
O
H
+
H
H2O
+
Hydrogen
bonds
Cohesion Properties
• Hydrogen bonds hold water molecules together
cohesion
• Cohesion transports water against gravity in plants
FURTHERMORE:
• Surface tension is a measure of how hard it is to break the
surface of a liquid
• Surface tension is related to cohesion
Water-conducting cells
(Phloem & Xylem)
100 µm
Animation: Water Transport
Solvent Properties
• Solution?
– liquid that is a homogeneous mixture of substances
• Solvent?
– the dissolving agent of a solution
• Solute?
– the substance that is dissolved
THERFORE
• Water is a versatile solvent due to its polarity
• Aqueous solution?
– one in which water is the solvent
Water is an effective solvent because it readily forms
hydrogen bonds
–
Na+
+
+
–
–
+
–
–
Na+
–
+
+
Cl–
Cl–
+
–
+
+
–
–
–
–
3.2
Carbohydrates, Lipids,
& Proteins
• Cells  70–95% water,
• the rest consists mostly of carbon-based compounds like…
– Proteins, DNA, carbohydrates
• Carbon chains = the skeletons of most organic molecules
• Carbon chains vary in length and shape
• If Carbon is present, and in a living system, this is
considered to be ORGANIC, if NOT THEN INORGANIC
– Most also contain HYDROGEN
• YOU WILL ALSO BE REQUIRED TO IDENTIFY THE
FOLLOWING:
GLUCOSE, RIBOSE, AMINO ACIDS, AND FATTY ACIDS
• Glucose
– most important monosaccharide
– Glucose: C6H12O6 this is a hexose sugar (six carbons)
most commonly found in this ring structure in an
aqueous solution
– Glucose will be known mostly as a product of
photosynthesis or the substrate molecule for respiration.
– Glucose is also found in a polymer as starch, glycogen or
cellulose.
– All bonds are covalent.
Ribose:
– Pentose (5 carbon sugar).
– Ribose is used in photosynthesis as:
– ribulose bisphosphate. (RUBP)
– Where else is RIBOSE used?
– deoxyribose  Deoxyribonucleic acid or DNA
Amino Acids:
– How many?
– 20 common amino acids
– Amino acids are monomers which combine to form the
larger polypeptides.
– In turn polypeptides combine to make proteins.
– Proteins uses?
– enzymes and many cellular and extra cellular components.
– Each of the common amino acids has the same structure
as the one shown except that the R group is different.
Fatty Acids:
– These molecules are the basis of triglycerides and many other types of lipid.
– These molecules are also the basis of the phospholipid molecules that form
the bilayer of the cell membrane.
– This image shows a basic saturated (no double bonds) fatty acid.
H
H
H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
H
O
C
OH
– There is a methyl group (-CH3) at one end of the chain.
– Chain is the formed from a series of covalently bonded carbons saturated with
hydrogens.
– The chain is non-polar and hydrophobic
– The carbonyl group is polar making this ends of the molecule hydrophilic.
Fatty acids
H
H
H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
O
C
OH
H
Can be drawn as:
O
C
OH
Triglycerol
Most macromolecules are polymers,
built from monomers
• A polymer is a long molecule consisting of many
similar building blocks called monomers
• Some Carbohydrates serve as fuel and building
material, and are either monomers or polymers
• Monosaccharides
• Disaccharide
• Polysaccharides
 single sugars, only 1
 2 sugars
 many sugars
• Dehydration reaction  joins 2 monosaccharides to
form Di or Poly
Some Functions of Common Carb’s
Example
Type of Carb
Function
Glucose
(MOST COMMON)
Monosaccharide
Energy source in animal cells
Glucose
Monosaccharide
Component of flower nectar
Lactose
Disaccharide
Sugar found in milk
Sucrose
Disaccharide
Transport form of carb’s in
phloem
Glycogen
Polysaccharide
Carbs storage in liver of
animals
Cellulose
Polysaccharide
Component of plant cell
walls
Dehydration
reaction in the
synthesis of
maltose
1–4
glycosidic
linkage
Glucose
Dehydration
reaction in the
synthesis of
sucrose
Glucose
Maltose
1–2
glycosidic
linkage
Glucose
Fructose
Sucrose
STARCH  Poly made of many GLUCOSE
molecules stored in Chloroplasts!
Chloroplast
Starch
1 µm
Amylose
Amylopectin
Starch: a plant polysaccharide
Cellulose microfibrils
in a plant cell wall
Cell walls
Microfibril
0.5 µm
Plant cells
Cellulose
molecules
b Glucose
monomer
• Cellulose in human food passes through
the digestive tract as insoluble fiber
• Some microbes use enzymes to digest
cellulose
– COWS
– This is a SYMBIOTIC RELATIONSHIP Between
COW & MICROBE
So starch in plants, what about animal polysaccharides?
• GLYCOGEN
• Glycogen is a storage polysaccharide in animals
• Humans and other vertebrates store glycogen mainly in
liver and muscle cells
• Chitin, another structural polysaccharide, is found in
the exoskeleton of arthropods
• Chitin can be used as surgical thread
Mitochondria
Glycogen granules
0.5 µm
Glycogen
Glycogen: an animal polysaccharide
Synthesis & Breakdown of Polymers
• Monomers form larger molecules by condensation
reactions called dehydration reactions
• Polymers are disassembled to monomers by
hydrolysis, a reaction that is essentially the reverse of
the dehydration reaction
Lipids
• Lipids are non polar, so they do not dissolve in water
• The most biologically important lipids are fats,
phospholipids, and steroids
• The major functions of fats are:
- energy storage
- thermal insulation
- buoyancy
• Energy storage:
–
–
–
–
–
Fats are a more compact fuel than starch.
Fat contains twice the energy-rich (C-H) bonds as glucose
Fat stores twice as much energy as glucose
Fat produces twice as many calories when burned
Unfortunately, you need to put twice as much energy to burn
off a pound of excess fat than you do of glycogen.........
So which is likely to burn faster when an animal
is starving, lipids or glycogen stores?
GLYCOGEN
Therefore:
LIPIDS ARE USED FOR LONG TERM STORAGE,
NOT FAST ENERGY.
Uses of Lipids in Living Things
Long-term energy stores
Human Adipose Tissue
Plant Oils
Buoyancy for marine animals: lipids are less
dense than water so help animals float
Insulation: a layer of fat beneath the skin
cuts down heat loss
Production of water:
fatty acids produce a lot of metabolic water when they are used during cellular
respiration, for example...
C17H35COOH + 26 O2  18 CO2 + 18 H2O
(a typical fatty acid)
Camels’ humps are an example of this
metabolic water production!
Furthermore, their erythrocytes can
swell to 240% of normal size without
bursting. (Other species can only go to
150%.)