Biology and Chemistry

6.3 __________________

6.4 __________________

Water• Water __________________

– ________________________________________________________________________

• Has a _________________________________• These special properties make water act like a

________!• Water helps

_______________________________

Polar Molecules ________________________

Mixtures with water: SOLUTIONS

• Water is considered to be the universal solvent __________________________________________

• A simple solution is _________________________________________

• A solute __________________________________________

• The solvent ___________________________________________

• As a rule of thumb, _______________________________________

Mixtures• Mixture

– A _____________________________________________• Homogenous mixtures

– Is the same throughout the entire mixture– _____________________________________________– Ex: Lemonade (____________________________)

• Heterogeneous mixtures– _____________________________________________– You could pick the pieces apart– Ex: Salad (_________________________________)– Includes COLLOIDS which are kind of strange

• Ex: _____________________________________________

Comprehension Check• Why is water considered the “universal

solvent”?

• Name one common heterogeneous solution.

• Name one common homogeneous solution.

Acids and Bases

• Acids and bases _____________________________________________ _____________________________________________

• Acids– A dissolved substance __________________(hydrogen ion)

– The more H+, ___________________________

• Bases– A dissolved substance ___________________(hydroxide ion)

– The more OH-, _________________________________

pH and Buffers

• pH scale_____________________________________________ ____________________________________________

• Neutral_____________________________________________ _____________________________________________

• Buffers_____________________________________________ Ex: You blood must be at a pH of 7.4, there are buffers in your blood to keep the pH at this range

Oven cleaner

Bleach

Ammonia solution

Soap

Sea water

Human bloodPure waterMilkNormalrainfall

Acid rainTomatojuice

Lemon juice

Stomach acid

NeutralIn

crea

sing

ly B

asic

Incr

easi

ngly

Aci

dic

pH scale

Neutral : equal Neutral : equal amounts of OH- amounts of OH- and H+and H+

Acid: more H+Acid: more H+

Base: more OH-Base: more OH-

Biochemistry Scientists studied Ramshorn snails. Each aquaria contained the same

number of Ramshorn snails, but had differing pH values as shown:Aquaria A – 6.0pH Aquaria B – 10.0pHAquaria C – 12.0pHAfter four months a high percentage of the snails in the aquaria A had

exterior shell damage from dissolving. The snails in aquaria B and C had no shell damage and seemed to be thriving. What was most likely being studied in this experiment?

a. The relationship between pH and the temperature of pond water. b. The effect of predators on the population size of Ramshorn snails. c. The effect of acid rain on the Ramshorn snails. d. The effect of density on the growth of Ramshorn snails.

Testing for pH

• _________: put a drop of the solution on the paper and then compare it to the colors on the key

• ____________

– ____________• Blue paper will turn red in acid (BRA)

– ____________• Red will turn blue in base (BB)

Comprehension Check

• What makes something an acid?

• What makes something a base?

• What are the two testing solutions used when working with pH?

Carbon Carbon Everywhere….• Organic Compounds: these compounds

contain carbon, they are the basis for life (all living things contain carbon)

Examples: Carbs, sugars, fats, proteins, nucleic acids

• Inorganic Compounds: these compounds do not contain carbon

Examples: WATER, Salt, Vitamins,

Carbon Dioxide???

Macromolecule: “giant” molecules found in living cells, they are formed by linking together many smaller units into a larger unit (4 majors ones in all living things!)

Smaller units: monomers(mono=one)

Larger units: polymers(poly=many)

Organic Molecules

Types of Organic Compounds

Carbohydrates

Lipids

Proteins

Nucleic Acids

Comprehension Check

• What do all organic compounds have in common?

• What are the four main types of organic compounds?

Carbohydrates

Monomer: Monosaccharide (Sugar)

Polymer: Disaccharides (Sugar), Polysaccharides (Starch)

Main functions:– Energy– Structure (plants and

arthropods)

Testing for Carbohydrates• Monosaccharide (Sugar)

Benedict’s Test – Add equal parts of the solution

and benedicts– Heat for a few minutes– Bright Colors = Sugar Present

• Polysaccharide (Starch) Iodine Test– Add equal parts of the solution

and iodine– If it turns black/dark purple

there is starch present

Comprehension Check

• What is the other word for sugar?

• What is the other word for starch?

Proteins• Monomer: Amino Acid

– There are 20 types of amino acids, but they all have the same basic structure

• Polymer: Polypeptide • main functions of proteins:

– Build body tissues, nails, hair– Helps reactions in your body occur faster

Test for Protein

• Protein Test Biuret’s Test– Add equal parts solution

and biuret– If the solution turns

lavender then there is protein present

Nucleic AcidsMonomer: Nucleotide

Polymer: DNA, RNA

• Function– Store and transmit

genetic information

Lipids • Monomer: Fatty Acid

• Polymer: Fatty Acid with extended tails

• Insoluble in water!! Why??– Non-polar

• Main functions:

1. Storage of Energy2. Major component of cell

membranes

Examples: fats, oils, waxes, steroids, hormones

Testing for Lipids

• Lipid (Fat) Test Brown Paper Towel Test– Add and few drops of the solution to a BROWN paper towel– Wait for the solution to DRY– If it is transparent there is lipid present