H.L. Biology Unit 2.1-2.7 (Basically just LO1: Molecules)

How many bonds can carbon form?

Four covalent bonds

What does the ability to have up to four covalent bonds allow carbon to do?

This characteristic allows for diversity in molecular structure by allowing carbon to branch off in four different directions

What are carbon-based compounds made by/found in living things called?

Organic Compounds

What do we call compounds made of only hydrogen and carbon? What is one example?

Hydrocarbons, Methane (CH₄)

What is a chain of carbons called?

A carbon skeleton/backbone, which is the foundation of organic molecules

What are the four classes of biological molecules? What is the other name used to refer to this group of molecules?

Proteins, lipids, nucleic acids, carbohydrates - Macromolecules

What is Anabolism?

The process of using simpler molecules to build complex molecules

What is Catabolism?

The process of breaking down complex molecules into simpler molecules

What is Metabolism?

The web of all catabolic and anabolic reactions in an organism

What kind of reaction is required during anabolism?

Condensation reactions that remove water molecules to form bonds

What kind of reaction is required during catabolism?

Hydrolysis reactions that break bonds by adding water molecules

What elements are carbohydrates made of?

C, H, O

What are the functions of monosaccharides like glucose?

Provides energy for cellular work, used as raw materials for organic molecules

What are the functions of polysaccharides like starch?

Short-term energy storage

What are the functions of polysaccharides like cellulose?

Structural support

Name 3 monosaccharides

Glucose, Fructose, Galactose

What do monosaccharides combine to form?

disaccharides, polysaccharides

Name 3 common disaccharides and the monosaccharides that form each of them.

1. Maltose: Glucose + Glucose

2. Sucrose: Glucose + Fructose

3. Lactose: Galactose + Glucose

What characteristic allows monosaccharides to be easily transported in fluids?

They dissolve easily without losing structure

Describe the structure of Alpha and Beta glucose

The right side of Alpha glucose is in order as H, C, OH, while the right side of Beta glucose is in order as OH, C, H

List the following details about starch:

1. Function and where it is found

2. What polysaccharides it is made of

1. A storage polysaccharide found in plants

2. Made amylose and amylopectin, who are formed by alpha glucose monomers

What is amylose?

A continuous helical chain of 1-to-4 glycosidic bonds

What is amylopectin?

A globular branched polymer of glucose with 1-to-4 and 1-to-6 glycosidic bonds that cause them to branch

List the following details about glycogen:

1. Function and where it is found

2. What it is made of

1. A storage polysaccharide found in animals

2. Made of alpha glucose monomers, some similar to amylopectin but with more branching

How does the usage of insulin as a diabetes treatment relate to glycogen?

Insulin groups glucose into glycogen, reducing the amount of sugar in your blood. When the sugar is needed, it can be broken back down into glucose.

List the following details about cellulose:

1. Function and where it is found

2. What it is made of

1. A structural polysaccharide used for cell walls found in plants

2. Made of alternating beta glucose monomers that allow them to be arranged into straight strands of polymers

List the following details about chitin:

1. Function and where it is found

2. What it is made of

1. A structural polysaccharide used for cell walls and exoskeletons found in fungi and insects

2. Made of beta glucose monomers

Are polysaccharides hydrophilic or hydrophobic?

Hydrophilic

What elements are carbohydrates made of?

C, H, O

How do lipids compare to carbohydrates in terms of energy storage?

Lipids contain more energy per gram and are better for long term energy storage because they are more difficult to hydrolyze

Are lipids hydrophilic or hydrophobic?

Hydrophobic

What are triglycerides? (fats)

One glycerol group linked to three carbon chains by the anabolic process of condensation

What is another name for the carbon chains on triglycerides?

Fatty acid tails

What is the difference between triglycerides and phospholipids?

Phospholipids have a phosphate group that replaces one fatty acid tail

What is the difference between the structure of a Saturated Fat and an Unsaturated fat?

Unsaturated fats have carbon double bonds in their carbon chains that cause the chain to have less hydrogens. This causes a bend in the fatty acid tails.

Why do the structures of Unsaturated Fats make them healthier than Saturated fats?

The bend in their carbon chains makes it harder for them to stack on top of each other, so they tend to be more fluid. This helps maintain cholesterol levels and membrane fluidity.

What organisms are Saturated Fats usually found in?

Animals

What organisms are Unsaturated Oils usually found in?

Plants

What do you call a triglyceride with only one double carbon bond?

Monounsaturated Fat

What do you call a triglyceride with multiple double carbon bonds?

Polyunsaturated Fat

What is Adipose Tissue?

Layers of connective tissue below the skin/between organs that acts as insulation, energy storage, and a cushion for organs.

What is cholesterol?

A steroid (type of lipid) whose structure is used as a blueprint for the production of other steroids like sex hormones (testosterone, estrogen)

What characteristics allow steroids to easily travel through cell membranes?

They are nonpolar and hydrophobic

What is the “goldilocks zone” as it relates to Earth?

The goldilocks zone refers to the phenomenon of Earth being the perfect distance away from the sun, allowing it to bear water and life.

Where did Earth’s water likely come from?

Asteroids and comet collisions

What do astrobiologists often look for when searching for the potential of life outside of earth?

They look for planets that can bear liquid water, since life on Earth began with water

What type of bond holds atoms within water molecules together?

Hydrogen Bond

Describe water molecule polarity

Oxygen is partially negative and hydrogen is partially positive, so the hydrogen atoms get pulled towards the oxygen atom and create a polar molecule

What three characteristics does hydrogen bonding give water?

1. High specific heat capacity

2. High latent heat of vaporization

3. Efficient heat conductor

What is specific heat capacity?

The amount of energy required to raise the temperature of a substance by one degree

What is latent heat of vaporization?

The amount of energy required to turn a liquid into a vapor

What two properties of water has a large affect on the lives of animals like the ringed seal and the black-throated loon?

Buoyancy and Viscosity - The body shapes of marine animals like the ringed seal have changed to adapt to water’s viscosity and to remain buoyant

What physical adaptations does the ringed seal have in order to thrive in water?

Aerodynamic body shape, flippers/tail with flukes, small amount of short fur

What is cohesion? How does this affect water?

The attraction between particles of a substance - this creates the shape of water drop when water molecules stick together

What is adhesion? How does this affect water?

The attraction between particles of two different substances - water is polar so it can adhere to other polar substances

What is surface tension? How does this relate to water?

The inward force that tends to minimize the surface area of liquids due to cohesion - Water tends to have high surface tension

What is capillary action? How does this relate to water?

The rise of liquids up very narrow tubes caused by adhesion and cohesion - this is how water travels up the xylem of plants

Is water a versatile solvent? Give an example of this characteristic.

Yes, water is a versatile solvent that can dissolve a variety of solutes - Blood plasma is 90% water, which lets it dissolve nutrients.

What are lipoproteins?

A group of soluble proteins used to transport other hydrophobic lipids through substances made mostly of water.

What are Low-Density Lipoproteins?

“Bad cholesterol” that makes up most of our body’s cholesterol and may cause heart disease/stroke at high levels.

What is plaque?

The build up of low density lipoproteins on the walls of blood vessels that may cause arteries to constrict, decreasing blood flow.

What are High-Density Lipoproteins?

“Good cholesterol” that absorbs cholesterol and carries it to the liver to be flushed out of the body and decreases chances for heart disease/stroke at high levels

What are proteins?

Macromolecules consisting of polypeptides: long chains of amino acids linked together by condensation

What is the R group of an amino acid?

A variable group attached to an amino acid that determines its characteristics and function

What is the difference between essential and non-essential amino acids?

Essential amino acids can only be obtained through food because they cannot be synthesized, while non-essential amino acids can.

How many naturally occurring amino acids are there?

20 that ribosomes combine in different orders to create a variety of polypeptides

What are prosthetic groups? What is an example?

Non-amino acids portions of a protein - Hemoglobin contains iron used to bond to oxygen atoms

What is the difference between Conjugated and Non-conjugated proteins?

Conjugated proteins contain prosthetic groups while non-conjugated proteins do not

What is an example of a conjugated protein? A non-conjugated protein?

Hemoglobin, insulin

What happens to proteins at extreme temperatures or pH values?

They denature, losing their shape and therefore their function

What is the Primary Structure of a protein?

The sequence of amino acids that make up its polypeptide chain

What bonds hold amino acids together?

Peptide bonds

What is the Secondary Structure of a protein?

Regions of the polypeptide backbone that are stabilized by hydrogen bonds between the hydrogen and carboxyl groups of amino acid subunits, found as local, repetitive folding patterns

What are the two types/shapes of Secondary Structure?

Alpha Helix and Beta Pleated

What is the Tertiary Structure of a protein?

Several types of interactions among the R groups within a polypeptide that stabilize the overall 3D structure of a protein molecule

What are different types of Tertiary Structure and what are they caused by?

1. Disulphide Bridge - Sulfur in R group

2. Ionic Bonds - Polar molecules in R group

3. Hydrogen Bonding - Hydrogen in R group

4. Hydrophobic Interaction - Non-polar molecules in R group

What is Quaternary structure? Why do certain proteins not have this structure?

Interactions between multiple polypeptide chains. Some proteins only have one polypeptide, so they will not have quarternary structure.

What are enzymes?

Globular proteins that accelerate chemical reactions in living systems

What are substrates?

Molecules that enzymes work on through condensation and hydrolysis

How do substrates attach to enzymes?

They collide by random molecular motion then bind onto the active site through condensation

What does it mean when an enzyme is saturated?

The state of an enzyme where it cannot hold more substrate than it already is

What is an enzyme-substrate complex?

The structure formed after substrates bond to an enzyme

What kind of change does an enzyme-substrate complex go through in order to change its shape?

Conformational change to create an induced fit with its substrate

Why are enzymes beneficial?

They lower the amount of activation energy needed for reactions, which prevents proteins from denaturing under immense heat.

What are 2 ways enzymes lower the activation energy needed for chemical reactions?

1. They hold molecules in place so they don’t expend energy moving about until they collide by random molecular motion

2. They undergo conformational change to break apart or bring together substrates

What is the relationship between temperature/pH and enzymes?

Enzymes lose shape in extreme temperatures/pH (range depends on enzyme), becoming denatured

What is the relationship between substrate and enzymes?

Enzymes increase in reaction rate proportionally to the concentration of substrate until their point of saturation, where the reaction rate will plateau because the enzyme cannot hold more substrate.

What are nucleic acids?

Large molecules that code genetic information

What are the monomers of Nucleic Acids called? The polymers?

Nucleotides, Polynucleotides

What are the three parts of a Nucleotide?

Phosphate, pentose sugar, nitrogenous base

What are the five nitrogenous bases?

Adenine, Thymine, Cytosine, Guanine, Uracil

List the three nitrogenous base pairs

Adenine-Thymine, Cytosine-Guanine, Adenine-Uracil

What are 3 differences between RNA and DNA?

DNA: Double Stranded, Deoxyribose Sugar, ATCG bases

RNA: Single Stranded, Ribose Sugar, AUCG bases

What is the difference between Deoxyribose and Ribose?

Deoxyribose has an H group in the bottom right corner while ribose has an OH group in the same position

What bonds connect molecules within nucleotides?

Covalent bonds

What bonds connect nucleotides to other nucleotides to form a polynucleotide?

Covalent phosphodiester bonds

The process of DNA replication is semi-conservative. What does this mean?

Half of a newly made DNA molecule will be from old material and half will be from new material, since the old material is used as a template

List the five enzymes involved in DNA replication in chronological order following the replication process

1. Helicase

2. Primase

3. Polymerase III

4. Polymerase I

5. (Polymerase III)

6. Ligase

What is the role of Helicase in DNA replication?

It unzips the double helix by breaking the hydrogen bonds between base pairs

What is the role of Primase in DNA replication?

creates a primer out of RNA that serves as a starting point for DNA polymerase to begin DNA synthesis