Download Chemistry of Life 3a Puzzle Paragraph

The Chemistry of Life Puzzle Paragraph
Water
Water molecules consist of two hydrogen atoms bonded to an oxygen atom. The hydrogen atoms have a
slight ____________ charge and the oxygen atom has a slight ____________ charge. So, water molecules
have two poles – a positive hydrogen pole and a negative oxygen pole. This feature of a molecule is called
____________. A bond can form between the positive pole in one water molecule and the negative pole of
another. This is called a ____________ bond. In liquid water many of these bonds form, giving water
properties that make it a very useful substance for living organisms.
Properties of Water
1. ____________
Water molecules stick to each other because of the hydrogen bonds that
form between them. Water is used as a transport medium in the xylem of
plants.
2. ____________
Many different substances dissolve in water because of its polarity
(sodium ions, glucose, enzymes). Water is the medium for metabolic
reactions.
3. Thermal Properties: ____________ ____________
Water has a large heat capacity-large amounts of energy are need to raise
its temperature, to break some of the hydrogen bonds. Blood, which is
mainly composed of water, is used as a transport medium for heat.
4. Thermal Properties: ____________ ____________
The boiling point of water is 100*C because in order for it to change from
a liquid to a gas all of the hydrogen bonds between the water molecules
have to be broken.
5. Thermal Properties: ____________ ____________ ____________
Water can evaporate at temperatures below boiling point. Hydrogen bonds
have to be broken to do this. The heat needed to break the bonds is taken
from the liquid water, cooling it down. Water is a coolant (sweat,
transpiration from plants)
Elements in Living Organisms
The four most common chemical elements of life are carbon, hydrogen, oxygen, and
nitrogen. They are apart of all the main organic compounds in living organisms.
1. ____________ (S)
Needed to make two of the twenty amino acids that proteins contain.
2. ____________ (Ca)
Acts as a messenger, binding to calmodulin and other proteins that
regulate processes inside cells, including transcription.
Ex: minerals that strengthen teeth and bones
3. ____________ (P)
Part of the phosphate groups in ATP and DNA molecules
4. ____________ (Fe)
Needed to make cytochromes-proteins used for electron transport during
aerobic cell respiration. Ex: makes hemoglobin
Organic Compounds
Compounds containing ____________ that are found in living organisms. (carbohydrates,
lipids, and proteins)
Inorganic Compounds
All compounds that contain no carbon are ____________. There are a few carbon
compounds that are inorganic even though they can be found in living organisms->carbon
dioxide, carbonates, and hydrogen carbonates.
Condensation Reaction
In a condensation reaction two molecules are ____________ together for form a larger
molecule. ____________ is also formed in the reaction. For example, two amino acids can
be joined together to form a dipeptide by a condensation reaction. The new bond is called
a ____________ Linkage.
Peptide Linkage
Condensation of two amino acids to form a ____________ and ____________.
Polypeptide
Further condensation reactions can link amino acids to either end of dipeptide, eventually
forming a ____________ of many amino acids.
Polysaccharide
Condensation reactions are used to build up ____________ and ____________. The basic
subunits of carbohydrates are monosaccharides. Two monosaccharides can be linked to
form a disaccharide and more monosaccharides can be linked to a disaccharide to form a
large molecule called a polysaccharide.
Hydrolysis Reactions
Using ____________ molecules, large molecules such as polypeptides, polysaccharides and
triglycerides can be broken down into smaller molecules by hydrolysis reactions.
Hydrolysis reactions are the ____________ of condensation reactions.
Polypeptides + water -> dipeptides or amino acids
Polysaccharides + water -> disaccharides or monosaccharides
glycerides + water -> fatty acids + glycerol
Monosaccharides (Ex of Carbohydrate)
Glucose, galactose, fructose
____________ is carried by the blood to transport energy to cells throughout the body.
____________ is used to make fruits sweet-tasting, attracting animals to disperse seeds in
the fruit.
Disaccharides (Ex of Carbohydrate)
Maltose, lactose, sucrose
____________ is the sugar in milk, that provides energy to young mammals until they are
weaned. ____________ is carried by phloem to transport energy to cells throughout the
plant.
Polysaccharides
Starch, glycogen, cellulose
____________ is used as a short-term energy store in liver and in muscles. ____________ is
used to make strong fibers that are used to construct the plant cell wall.
Function of Lipids
____________ storage- in the form of fat in humans and oil in plants
____________ insulation- a layer of fat under the skin reduces heat loss
____________ - lipids are less dense that water so help animals to float.
Advantage of Lipids In Energy Storage
Lipids used for long-term storage of ____________. Lipids contain more energy per gram
than carbohydrates so stores of lipid are lighter than stores of carbohydrate that contain
the same amount of energy. ____________ are insoluble in water, so they do not cause
problems with osmosis in cells.
Advantages of Carbohydrates In Energy Storage
Carbohydrates are usually used for energy storage over ____________ periods.
Carbohydrates are more easily digested than lipids so the energy stored by them can be
released more rapidly. Carbohydrates are soluble in water so are easier to transport to an
from the store.
Nucleotides
Basic units of ____________ molecule, composed of a sugar (deoxyribose), a phosphate,
and one of 4 DNA bases (Adenine, cytosine, guanine, and thymine).
Enzymes
Enzymes are globular proteins which act as catalysts of chemical reactions. Without
enzymes to ____________ them, many chemical processes happen at a very slow rate in
living organisms. By making some enzymes and not others, cells can control what
chemical reactions happen in their cytoplasm.
Denaturation
Denaturation is changing the ____________ of an enzyme (or other protein) so that it can
no longer carry out is function. Usually Permanent.
Substrates
In chemical reactions, one or more reactants are converted into one or more products. In
reactions catalyzed by enzymes the reactants are called ____________.
Enzyme-Substrate Specificity
Most enzymes are ____________ - they catalyze very few different reactions. They
therefore only have a very small number of possible substrates. This is called enzymesubstrate specificity
Active Site
An active site is a region on the surface of an enzyme to which ____________ bind and
which catalyze a chemical reaction involving the substrates.
Factors Affecting Enzyme Activity
Temperature, pH, inhibitors and substrate concentration all affect the ____________ at
which enzymes catalyze chemical reactions.
Effect of Temperature
Enzyme activity ____________ as temperature increases, often doubling with every 10*C
rise. This is because collisions between substrate and active site happen more frequently
at higher temperatures due to faster molecular motion.
At high temperatures enzymes are ____________ and stop working. This is because heat
vibrations inside enzymes which break bonds needed to maintain the structure of the
enzyme.
Effect of pH
Optimum pH at which enzyme activity is fastest (pH of 7 is optimum for most enzymes).
As pH increases or decreases from the ____________, enzyme activity is reduced. Both
acids and alkalis can denature enzymes.
Effect of Substrate Concentration
At low substrate concentrations, enzyme activity increases steeply as substrate
concentration increases. This is because random collisions between substrate and active
site happen more frequently with ____________ substrate concentrations.
At high substrate concentrations most of the active sites are occupied, so raising the
substrate concentration has ____________ effect on enzyme activity.
Lactose-free Milk
Lactose is the sugar that is naturally present in milk. It can be converted into glucose and
galactose by the enzyme ____________.
lactose->(lactase)-> glucose + galactose