Bio study guide

What two elements make up a water molecule?

Hydrogen (2) and Oxygen (1).

What type of bond holds the water molecule together?(itself)

covalent bond.

What type of bond connects water molecules to each other?(other)

hydrogen bonds.

What does polarity mean?

having two opposite sides, like positive and negative charges. It is an uneven distribution of electrical charges.

Does water have one pole or two poles?

two poles and it is a dipole molecule.

What is the charge on the hydrogen atoms of water? What is the charge of the oxygen atom?

Hydrogen has a partial positive charge and oxygen has a partial negative charge.

Define cohesion.

when water molecules stick to other water molecules.

Define adhesion.

when water sticks to other things.

Define capillary action.

when water moves up tubes or narrow spaces against gravity.

Explain how cohesion and adhesion allow water molecules to move up a narrow tube in at least six sentences.

-Cohesion is when water molecules sticks to itself.

-Adhesion is when water sticks to other things. 

-Capillary action is when water moves up tubes or narrow spaces against gravity. 

-Cohesion holds the water molecules together so they stay linked as a continuous stream.

-Adhesion helps the water molecules stick to the walls of the tube or the narrow tube. 

-Together, adhesion pulls the water up the walls of the tube while cohesion drags the rest of the water molecules along behind it.

What is the name of the narrow tube that moves water in plants?

xylem.

Define surface tension.

an invisible, stretchy "skin" on the top of a liquid that makes it act like a thin, elastic film

What property of water is responsible for surface tension?

Cohesion is

Define specific heat.

how much heat a substance needs to increase its temperature, or how hard it is to heat something up.

Why does water have a high specific heat?

-Hydrogen bonds

-Water needs a lot of energy to increase its temperature

-Water can absorb a lot of heat without its temperature rising quickly.

Does water become more or less dense when it freezes?

less dense when it freezes because the molecules spread into a more open structure, which is why ice floats on water.

Why is it important for life that water floats when it freezes?

the ice forms a layer on top that keeps the water underneath from freezing, which lets animals that live in water survive.

Why is water a universal solvent?

because it can dissolve many different substances due to its polarity.

Explain how sweating works to cool the body in at least four sentences.

-When the body gets too hot, it produces sweat on the skin.

-Sweat releases water onto the skin.

-As the sweat evaporates, it takes heat away from the body and cools it down.

-Sweating helps the body maintain homeostasis by keeping its temperature stable.

Sweating cools your body by releasing water onto your skin, which takes away heat as it evaporates, maintaining homeostasis

Explain why lipids are not water soluble in at least four sentences.

-Lipids are not water soluble because they are nonpolar, while water is polar.

- Water molecules are attracted to other polar molecules, but they are not attracted to lipids.

-Because of this, lipids do not mix well with water. 

-Instead, lipids separate from water and form a different layer.

What are the four macromolecules?

carbohydrates, lipids, proteins, and nucleic acids.

What is the monomer of carbohydrates?

monosaccharides.

What carbohydrate-derived substance makes up plant cell walls?

Cellulose

Plants store excess carbohydrates in what form?

starch.

Animals store excess carbohydrates as what for quick energy?

glycogen

Lobsters use carbohydrates to make what, the main component of their exoskeleton?

chitin

What is the monomer of lipids?

glycerol and fatty acids.

What type of hormones are lipids?

Steroid

What are two differences between saturated and unsaturated fats?

Saturated fats:

no double bonds in their fatty acid chains

Solid at room temperature

Unsaturated fats:

one or more double bonds

liquid at room temperature

Are saturated fats solid at room temperature?

Yes

What is the monomer of proteins?

amino acids.

Be able to label the amine group, R group, and carboxyl group of amino acids.

The amine group is NH₂, the R group varies between amino acids, and the carboxyl group is COOH.

Be able to tell how many amino acids are in a structural diagram of a protein.

Count the individual amino acid units in the protein chain.

What type of bond connects amino acids in a protein?

A peptide bond.

What structural group is found at the beginning of a protein? At the end?

The amine group and carboxyl group

What type of bond connects glycerol to fatty acids in lipids?

An ester bond.

What type of bond connects the monomers of carbohydrates?

A glycosidic bond.

What does a peptide, ester, and glycosidic bond connect?

Peptide bond = connects amino acids.

Ester bond = connects glycerol and fatty acids.

Glycosidic bond = connects carbohydrate monomers.

Name at least one protein that acts as a hormone.

Insulin.

What type of protein acts as a catalyst?

An enzyme.

Which macromolecule contains the most energy?

Lipids.

What is the name of the molecule that an enzyme acts on?

Substrate.

What is the name of the site on an enzyme where substrates bind?

Active site.

What are the two factors that affect the function of enzymes?

Temperature and pH.

What are the two types of inhibition?

Competitive inhibition and non-competitive inhibition.

What is an allosteric site?

A site on an enzyme away from the active site where a molecule can bind and change the enzyme's shape.

Draw a graph showing substrate concentration and enzyme reactivity. Be able to explain this relationship.

As substrate concentration increases, enzyme reactivity increases at first. Eventually, the reaction rate levels off because all the enzyme's active sites are occupied.

How do enzymes speed up reactions?

lowering the activation energy needed for the reaction.

Are enzymes destroyed in the reaction that they catalyze?

No they can be used again.

Explain how isoleucine works as an example of non-competitive inhibition.

-binds to an allosteric site on the enzyme

-changes its shape

-making the active site work less effectively.

-Adding more substrate cannot fully overcome this type of inhibition

What is one example of a competitive inhibitor?

Malonate competes with the substrate for the enzyme's active site.

What is the monomer of nucleic acids?

Nucleotides.

What are the three examples of nucleic acids?

DNA, RNA, and ATP.

Which macromolecule contains sulfur?

Proteins.

Which two macromolecules contain nitrogen?

Proteins and nucleic acids.

Which macromolecule can be identified by its phosphate group(s)?

Nucleic acids.

What is the enzyme that breaks down starch?

Amylase.

What is the name of the reaction that makes macromolecules?

Dehydration synthesis.

What is the name of the reaction that breaks down macromolecules?

Hydrolysis.

Explain the relationship between temperature or pH and enzyme activity in at least four sentences.

-First, enzymes work best at a specific temperature and pH. 

-Second, increasing temperature can increase enzyme activity until it reaches the optimal temperature. 

-Third, temperatures that are too high can change the enzyme's shape and cause it to stop working properly. (denature)

- Fourth, pH levels that are too high or too low can also change the enzyme's shape and decrease its activity.

Be able to outline the properties of water that are important for life in a minimum of four sentences.

-Water has a high Specific heat, which helps keep temperatures stable. 

-Second, water is a universal solvents, so it can dissolve many substances needed by living things. 

-Water has cohesion which creates surface tension. 

-Ice is less dense than liquid water, so it floats and helps aquatic life survive.

Be able to identify all macromolecules by shape or structure CARBOHYDRATES

Look like rings

CHO

monosaccharides disaccharides, or polysaccharides

OSE

Be able to identify all macromolecules by shape or structure LIPIDS

long fatty-acid tails

CHO

long glycerol backbone

Be able to identify all macromolecules by shape or structure PROTEINS

folded chains of amino acids

CHON

Amine group (NH2) Carboxly group (COOH)

Be able to identify all macromolecules by shape or structure NUCLEIC ACIDS

repeating phosphate

sugar

nitrogen-base units,

CHONP