Chapter 4

The term organic is used to describe the enormous number of compounds that contain carbon—specifically ____ or _____bonds.

The term organic is used to describe the enormous number of compounds that contain carbon—specifically COC or COH bonds.

In the human body, the following four major groups of organic substances are very important:

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic acids and related molecules

The term _______________ groups is often used to describe certain arrangements of atoms attached to the carbon core of many organic molecules

The term functional groups is often used to describe certain arrangements of atoms attached to the carbon core of many organic molecules

Functional groups—also called __________—often go into and out of combination with large organic molecules. Organic radicals are often designated simply as R.

Functional groups—also called radicals—often go into and out of combination with large organic molecules. Organic radicals are often designated simply as R.

A ________ radical is a functional group that is temporarily unattached and is highly reactive because of unpaired electrons. Because it is ready to form a covalent bond, it will combine with another molecule within a small fraction of a second after it is free.

A free radical is a functional group that is temporarily unattached and is highly reactive because of unpaired electrons. Because it is ready to form a covalent bond, it will combine with another molecule within a small fraction of a second after it is free.

All ________________ compounds contain the elements carbon, hydrogen, and oxygen—usually in the ratio of ______.

All carbohydrate compounds contain the elements carbon, hydrogen, and oxygen—usually in the ratio of 1:2:1.

The carbon atoms link to one another in chains or rings. Carbohydrates include the substances commonly called ______ and _______.

The carbon atoms link to one another in chains or rings. Carbohydrates include the substances commonly called sugars and starches.

Carbohydrates provide the primary source of chemical energy needed by every cell in the body. They also have other functions… what are they? it is a table example.. 5 functions total. S

As a group, carbohydrates are divided into three types or classes that are characterized by the length of their carbon chains. The three types are named as follows:

1. Monosaccharides (simple sugars)

2. Disaccharides (double sugars)

3. Polysaccharides (complex sugars)

_______________________, or simple sugars, are relatively small carbohydrates. What is the most important simple sugar?

Monosaccharides, or simple sugars, are relatively small carbohydrates. Glucose is most important.

What is a 6-carbon sugar with the formula C6H12O6 ?

Glucose

What is also called Hexose?

Glucose

Glucose is present in the dry state as a straight chain but curls into a _________compound (ring) when dissolved in water.

Glucose is present in the dry state as a straight chain but curls into a cyclic compound (ring) when dissolved in water.

In addition to glucose, other important hexoses, or six-carbon simple sugars, include ________ and _________.

In addition to glucose, other important hexoses, or six-carbon simple sugars, include fructose and galactose.

Are all monosaccharides hexoses?

Some are pentoses (from penta, “five”), so named because they contain five carbon atoms. Ribose and deoxyribose are pentose monosaccharides

What are carbohydrates composed of two or more simple sugars that are bonded together through a dehydration synthesis reaction that involves the removal of water?

disaccharides (double sugars)

or

polysaccharides (complex sugars)

_____________ consist of many monosaccharides chemically joined to form straight or branched chains.

Polysaccharides consist of many monosaccharides chemically joined to form straight or branched chains.

Once again, water is removed as the many monosaccharide subunits are joined. Any large molecule made up of many identical small molecules is called a ______________

Once again, water is removed as the many monosaccharide subunits are joined. Any large molecule made up of many identical small molecules is called a polymer

Polysaccharides are polymers of _____________________.

Polysaccharides are polymers of monosaccharides.

Glycogen, a polymer of ___________, is sometimes referred to as animal starch.

Glycogen, a polymer of glucose, is sometimes referred to as animal starch.

Lipids, according to one definition, are _________-insoluble organic biomolecules.

Lipids, according to one definition, are water-insoluble organic biomolecules.

Why do lipids not dissolve in water?

• non polar

• Electrons are equally shared within a molecule. They are stable.

• They do not cling to the partially charged areas of the polar water molecules

Will lipids dissolve in any solution?

Although insoluble in water, most lipids, many with an oil-like consistency and greasy feel, dissolve readily in some organic solvents such as ether, alcohol, or benzene.

Like the carbohydrates, lipids are composed largely of carbon, hydrogen, and oxygen. However, the proportion of oxygen in lipids is much ________than that in carbohydrates.

Like the carbohydrates, lipids are composed largely of carbon, hydrogen, and oxygen. However, the proportion of oxygen in lipids is much lower than that in carbohydrates.

Classification of lipids includes (4 types)

triglycerides or fats

phospholipids

steroids,

and prostaglandins (PGs).

Human Lipids have 6 functions in the body… (sorry future self)

____________________, or fats, are the most abundant lipids, and they function as the body’s most concentrated source of energy.

Triglycerides (triacylglycerols), or fats, are the most abundant lipids, and they function as the body’s most concentrated source of energy.

Two types of building blocks are needed to synthesize or build a fat molecule: _________ and __________.

Two types of building blocks are needed to synthesize or build a fat molecule: glycerol and fatty acids.

Describe a glycerol unit

Each glycerol unit is joined to three fatty acids,

and the glycerol building block is the same in each fat molecule.

Therefore it is the specific type of fatty acid molecule or component that identifies and determines the chemical nature of any fat.

How do Fatty acids vary?

• length of their carbon chains (number of carbon atoms)

• the number of hydrogen atoms that are attached to, or “saturate,” the available bonds around each carbon in the chain.

Naturally occurring fatty acids have an even number of carbons, usually numbering between ____ and _____.

Naturally occurring fatty acids have an even number of carbons, usually numbering between 12 and 18.

By definition, a saturated fatty acid is one in which all available bonds of its hydrocarbon chain are filled—that is, saturated—with _________ atoms.

By definition, a saturated fatty acid is one in which all available bonds of its hydrocarbon chain are filled—that is, saturated—with hydrogen atoms.

How do unsaturated fatty acids differ to saturated ?

an unsaturated fatty acid has one or more double bonds in its hydrocarbon chain because not all the chain’s carbon atoms are saturated with hydrogen atoms.

______________ fatty acids have only one double carbon bond in their chain, and _______________fatty acids have more than one double bond.

Monounsaturated fatty acids have only one double carbon bond in their chain, and polyunsaturated fatty acids have more than one double bond.

Fats become more oily and liquid as the number of unsaturated double bonds ______________.

Fats become more oily and liquid as the number of unsaturated double bonds increases.

The kinks and bends in the unsaturated molecules keep them from fitting closely together. In contrast, the lack of kinks in saturated fatty acids allows the molecules to fit tightly together to form a solid mass at higher temperatures.

glycerol tricaproate, suggests that it contains what for structure?

three molecules of the six-carbon fatty acid caproic acid attached to a glycerol molecule.

Caproic acid is considered to be a ___________ fatty acid; some triglycerides contain fatty acids with a carbon backbone several times longer, thus forming long-chain fatty acids.

Caproic acid is considered to be a short-chain fatty acid; some triglycerides contain fatty acids with a carbon backbone several times longer, thus forming long-chain fatty acids.

Phospholipids are lipid compounds similar to triglycerides. How do they differ?

, in that one of the three fatty acids attached to glycerol in a triglyceride is replaced in a phospholipid by another type of chemical structure containing phosphorus and nitrogen.

A small number of phospholipids in each cell of the body play a completely different role: They are regulatory molecules. Called ________________, these phospholipids have a huge impact on the complex functions of the cell.

A small number of phospholipids in each cell of the body play a completely different role: They are regulatory molecules. Called phosphoinositides (PIs), these phospholipids have a huge impact on the complex functions of the cell.

____________ are a large and important class of lipids whose molecules have as their main feature the steroid nucleus

Steroids are a large and important class of lipids whose molecules have as their main feature the steroid nucleus

The steroid nucleus is composed of _______attached rings that are structurally similar but may have widely diverse functions related to the differing functional groups that are attached to them.

The steroid nucleus is composed of four attached rings that are structurally similar but may have widely diverse functions related to the differing functional groups that are attached to them.

Steroids, some of which are called ___________, are widely distributed in the body and are involved in many important structural and functional roles.

Steroids, some of which are called sterols, are widely distributed in the body and are involved in many important structural and functional roles.

________________ is a steroid found in the plasma membrane surrounding every cell in the body

Cholesterol is a steroid found in the plasma membrane surrounding every cell in the body

Some functions of Cholesterol are ?

• Its presence helps stabilize this important cellular structure and is required for many reactions that cells must perform to survive.

• the body slightly modifies cholesterol molecules to form such important hormones as cortisone, estrogen, and testosterone.

  • used to make the bile salts needed for digestion.

The steroid nucleus is also a part of the active hormone form of vitamin D called _____________.

The steroid nucleus is also a part of the active hormone form of vitamin D called calcitriol.

_________________(PGs), often called tissue hormones, are lipids composed of a 20-carbon unsaturated fatty acid that contains a 5-carbon ring

Prostaglandins (PGs), often called tissue hormones, are lipids composed of a 20-carbon unsaturated fatty acid that contains a 5-carbon ring

The effects of PGs in the body are many and varied.

• They play a crucial role in regulating the effects of several hormones,

• influence blood pressure

• and the secretion of digestive juices

• enhance the body’s immune system

• and inflammatory response,

• and have an important role in blood clotting and respiration

Aspirin and bloodclotting .. what of it?

Prostaglandins sometimes serve to regulate blood clotting. Aspirin can inhibit prostaglandin synthesis and play a therapeutic role in preventing abnormal blood clots or reducing abnormal clots that have already begun forming. For this reason, some people at risk for a heart attack triggered by abnormal blood clots are advised to take daily low-dose aspirin to reduce the formation of abnormal clots.

All proteins have four elements:

carbon,

oxygen,

hydrogen,

and nitrogen.

Many proteins also contain small amounts of sulfur, iron, magnesium, zinc, and other trace metals.

What are the most abundant organic compounds in the body?

Proteins

Protein molecules are among the giant macromolecules, along with many of the __________ and _______acids.

Protein molecules are among the giant macromolecules, along with many of the polysaccharides and nucleic acids.

The many roles played by proteins in the body can be divided into two broad categories: _________ and ___________.

The many roles played by proteins in the body can be divided into two broad categories: structural and functional.

Structural proteins form what?

Structural proteins form

• the structure of the cells, tissues, and organs of the body.

• Various unique shapes and compositions such as flexible strands, elastic strands, and waterproof layers allow structural proteins to form the many different building blocks of the body.

Explain the role of functional proteins…

• Functional proteins are chemists.

• The unique shape of each functional protein allows it to fit with certain other chemicals and cause some change in the molecules.

• For example, enzymes are functional proteins that bring molecules together or split them apart in chemical reactions.

• Protein hormones such as insulin trigger chemical changes in cells to produce the hormone’s effects.

It is the _______or __________ of a protein that determines how it performs.

It is the shape or conformation of a protein that determines how it performs.

The main principle in understanding how proteins work is that form and function go hand in hand—the right shape for the right job.

Explain protein structure

• . They are chainlike polymers composed of multiple subunits, or building blocks, linked end to end.

• The building blocks of all proteins are called amino acids.

The building blocks of all proteins are called __________ acids.

The building blocks of all proteins are called amino acids.

The elements that make up a protein molecule are bonded together to form chemical units called ______ _______.

The elements that make up a protein molecule are bonded together to form chemical units called amino acids.

How many amino acids make up Proteins? how many are essential?

• Proteins are composed of 21 naturally occurring amino acids, and nearly all of the 21 amino acids are usually present in every protein.

• Of these 21, 8 are known as essential amino acids. They cannot be produced by the body and must be included in the adult diet.

• The 13 remaining nonessential amino acids can be produced from other amino acids or from simple organic molecules readily available to the body cells.

Explain the structure of a Protein

, it consists of a carbon atom (called the alpha carbon) to which are bonded a positive amino group (NH3+), a negative carboxyl group (COO−), a hydrogen atom, and a functional group or radical (R). It is this functional group that constitutes the unique, identifying part of an amino acid.

A ___________bond is one that binds the carboxyl group of one amino acid to the amino group of another amino acid.

A peptide bond is one that binds the carboxyl group of one amino acid to the amino group of another amino acid.

An O from the negative carboxyl group of one amino acid and two H atoms from the positive amino group of another amino acid split off to form water plus a new compound called a peptide.

An O from the negative carboxyl group of one amino acid and two H atoms from the positive amino group of another amino acid split off to form water plus a new compound called a ____________.

An O from the negative carboxyl group of one amino acid and two H atoms from the positive amino group of another amino acid split off to form water plus a new compound called a peptide.

A peptide made up of only two amino acids linked by a peptide bond is a _____________. A ___________ consists of three amino acids linked by two bonds.

A peptide made up of only two amino acids linked by a peptide bond is a dipeptide. A tripeptide consists of three amino acids linked by two bonds.

A long sequence or chain of amino acids—usually 100 or more—linked by peptide bonds constitutes a ______________

A long sequence or chain of amino acids—usually 100 or more—linked by peptide bonds constitutes a polypeptide

When the length of the polymer chain exceeds about 100 amino acids, the molecule is called a ___________ rather than a polypeptide.

When the length of the polymer chain exceeds about 100 amino acids, the molecule is called a protein rather than a polypeptide.

Do you see a similarity between the formation of a polysaccharide, such as glycogen, from simple sugar “building blocks” and the formation of a polypeptide from amino acid building blocks?

In both processes, many subunits are joined together, resulting in the loss of water molecules.

Thus both are examples of the condensation or dehydration synthesis reactions that are very common in living organisms.

A decomposition reaction called ___________ requires the addition of a water molecule to break a bond.

A decomposition reaction called hydrolysis requires the addition of a water molecule to break a bond.

Biochemists often describe four levels of increasing complexity in protein organization:

1. Primary (first level)

2. Secondary (second level)

3. Tertiary (third level)

4. Quaternary (fourth level)

Explain the primary structure of a protein

• The primary structure of a protein refers simply to the number, kind, and sequence of amino acids that make up the polypeptide chain.

• The hormone of the human parathyroid gland, parathyroid hormone (PTH), is a protein that retains its primary structure—it is a noodlelike molecule consisting of only one polypeptide chain of 84 amino acids.

Secondary protein structure

• Most polypeptides do not exist as a straight chain.

• they show a secondary structure in which the chains are coiled or bent into pleated sheets.

• The most common type of coil takes a clockwise direction and is called an alpha helix. In this type of secondary structure, the coils of the protein chain resemble a spiral staircase, with the coils stabilized by hydrogen bonds between successive turns of the spiral.

• Pleated beta sheets are likewise stabilized by hydrogen bonds. This stabilizing function of hydrogen bonding in protein structure is critical. A commonly occurring pattern of alpha helices and/or beta sheets within the secondary structure is called a motif. A motif often imparts a specific function to each protein in which it appears.

Tertiary protein structure

• secondary structure protein chain undergo other contortions and be further twisted so that a globular-shaped tertiary structure of a protein is formed.

• In this structure, the polypeptide chain is so twisted that its coils touch one another in many places, and “spot welds,” or interlocking connections, occur. Some of these linkages may be strong covalent bonds between amino acid units that exist in the same chain

• Most of the linkages are ionic bonds. Hydrogen bonds and other weak attractions also help stabilize the twisted and convoluted loops of the structure.

• A tertiary structure may include several complicated “knots” called domains. Each specific type of domain has specific functions that contribute to the overall function of a protein.

Quaternary protein structure

• A quaternary structure protein is one that contains clusters of more than one polypeptide chain, all linked together into one giant molecule.

• Antibody molecules that protect us from disease and hemoglobin molecules in red blood cells are examples.

• A group of proteins called chaperones, which are present in every cell in the body, acts to direct the steps required for many proteins to fold into the twisted and convoluted shape required for them to function properly. Some of these chaperone proteins are called chaperonins.

• Inappropriate folding of some proteins is known to be associated with certain diseases.

The final, functioning shape for a protein is often called its _________state

The final, functioning shape for a protein is often called its native state

The native states of the strong ___________ proteins found in tendons and ligaments are fibrous, or threadlike, insoluble, and very stable. In contrast, ____________ proteins such as enzymes, certain protein hormones, antibodies, albumin, and hemoglobin have native states that are globular (ball-shaped), are often soluble, and have chemically reactive regions.

The native states of the strong structural proteins found in tendons and ligaments are fibrous, or threadlike, insoluble, and very stable (Figure 4-15). In contrast, functional proteins such as enzymes, certain protein hormones, antibodies, albumin, and hemoglobin have native states that are globular (ball-shaped), are often soluble, and have chemically reactive regions.

List 7 functions of proteins

1. provide structure

2. catalyze chemical reactions

3. transport substances in blood

4. communicate information to cells

5. act as receptors

6. defend body against many harmful agents

7. provide energy

Give example of a Protein as a structure

Structural proteins include keratin of skin, hair, and nails; parts of cell membranes; tendons

Give example of a Protein as catalyst in chemical reactions

Lactase (enzyme in intestinal digestive juice) catalyzes chemical reaction that changes lactose to glucose and galactose

Give example of a Protein transporting substances in blood

Proteins classified as albumins combine with fatty acids to transport them in the form of lipoproteins

Give example of a Protein communicating information to cells

Insulin, a protein hormone, serves as a chemical messenger from islet cells of the pancreas to cells all over the body

Give example of a Protein acting as receptors

Binding sites of certain proteins on surfaces of cell membranes serve as receptors for insulin and various other hormones

Give example of a Protein defending body against harmful agents

Proteins called antibodies or immunoglobulins combine with various harmful agents to render those agents harmless

Give example of a Protein providing energy

Proteins can be metabolized for energy

What is it called when a protein loses its shape and as a consequence…its function?

Denatures

Factors that can cause a protein to denature include

1. changes in temperature,

2. changes in pH,

3. radiation,

4. and the presence of certain hazardous chemicals.

Can a protein RENATURE?

Depending on the circumstances, restoring the proper chemical environment of a protein may allow it to renature to its native state and begin functioning normally once again.

What does DNA and RNA stand for?

deoxyribonucleic and ribonucleic acids

Nucleic acid molecules are _____________ of thousands and thousands of smaller molecules called nucleotides—deoxyribonucleotides in DNA molecules and ribonucleotides in RNA molecules.

Nucleic acid molecules are polymers of thousands and thousands of smaller molecules called nucleotides—deoxyribonucleotides in DNA molecules and ribonucleotides in RNA molecules.

Nucleic acid molecules are polymers of thousands and thousands of smaller molecules called ___________

Nucleic acid molecules are polymers of thousands and thousands of smaller molecules called nucleotides—deoxyribonucleotides in DNA molecules and ribonucleotides in RNA molecules.

Describe the structure of DNA

1. A deoxyribonucleotide consists of the pentose sugar named deoxyribose

2. ,a nitrogenous base (either adenine, cytosine, guanine, or thymine),

3. and a phosphate group

How do ribonucleotides differ from deoxyribonucleotides?

Ribonucleotides contain the sugar ribose instead of deoxyribose and the nitrogenous base uracil instead of thymine

Compare DNA to RNA table… list the differences between the 2 in regards to

1. Polynucleotide strands

2. sugar

3. base pairing

What are PURINE BASES ?

1. Two of the bases in a deoxyribonucleotide, specifically adenine and guanine, are called purine bases because they derive from purine. Purines have a double-ring structure.

What derive from pyrimidine?

1. Cytosine and thymine derive from pyrimidine, so they are known as pyrimidine bases. Pyrimidines have a single-ring structure.

The pyrimidine base uracil replaces ___________ in RNA.

The pyrimidine base uracil replaces thymine in RNA.

_________molecules, the largest molecules in the body, are very large polymers composed of many ____________.

DNA molecules, the largest molecules in the body, are very large polymers composed of many nucleotides.

The nucleotides are joined together, _________ group to ___________group, by dehydration synthesis (condensation) to form a long sugar-phosphate backbone. Two of these long polynucleotide chains compose a single _________molecule.

The nucleotides are joined together, saccharide group to phosphate group, by dehydration synthesis (condensation) to form a long sugar-phosphate backbone. Two of these long polynucleotide chains compose a single DNA molecule.

Each helical chain in a DNA molecule has its phosphate-sugar backbone toward the ___________and its bases pointing _________toward the bases of the other chain. More than that, each base in one chain is joined to a base in the other chain by means of either two or three hydrogen bonds to form what is known as a ____________.

Each helical chain in a DNA molecule has its phosphate-sugar backbone toward the outside and its bases pointing inward toward the bases of the other chain. More than that, each base in one chain is joined to a base in the other chain by means of either two or three hydrogen bonds to form what is known as a base pair.

One important principle to remember is that only two kinds of base pairs are present in DNA. What are they?

A (adenine)-T(thymine) G(guanine)-C(cytosine)

Each RNA strand is a sequence of _________________that is essentially copied from a portion of a DNA molecule. Thus RNA molecules act as “temporary copies” of the master code of hereditary information in the DNA molecules. These RNA “copies” are involved in the process of protein synthesis.

Each RNA strand is a sequence of ribonucleotides that is essentially copied from a portion of a DNA molecule. Thus RNA molecules act as “temporary copies” of the master code of hereditary information in the DNA molecules. These RNA “copies” are involved in the process of protein synthesis.

Each RNA strand is a sequence of ribonucleotides that is essentially copied from a portion of a DNA molecule. Thus RNA molecules act as “___________” of the master code of hereditary information in the DNA molecules. These RNA “____” are involved in the process of protein synthesis.

Each RNA strand is a sequence of ribonucleotides that is essentially copied from a portion of a DNA molecule. Thus RNA molecules act as “temporary copies” of the master code of hereditary information in the DNA molecules. These RNA “copies” are involved in the process of protein synthesis.