Bio Chapter 3.

__________ are often hormones--> four fused rings

steroids

A nucleotide is made of what chemical components?

a nitrogenous base, a phosphate group, and a sugar

What happens when glucose forms a ring? (a) The molecule loses its carbonyl group. (b) The molecule loses one O atom. (c) The sixth C atom binds to the first C atom. (d) Both (b) and (c). (e) Both (a) and (c).

(a) The molecule loses its carbonyl group. The C=O group becomes -O-C-OH.

Hydrophobic

"water‐fearing"; pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water

Hydrophilic

"water‐loving"; pertaining to polar, or charged, molecules (or parts of molecules) that are soluble in water

_____ is the most abundant organic compound on Earth. (a) Cellulose (b) Glucose (c) Starch (d) Glycogen (e) Lactose

(a) Cellulose Cellulose, a component of plant cell walls, is the most abundant organic compound found on earth.

Dairy cattle were unknown in Thai culture until recently, and 97 percent of Thai people are lactose intolerant as adults. Which explanation for such widespread lactose intolerance is most likely correct? (a) Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful. (b) The ability to digest sugar in milk is determined by environment, and most humans are not exposed to milk as a food source beyond childhood years. (c) There is no good explanation for this situation in humans. (d) Allergies are becoming more common in humans as more chemicals are being encountered during longer lifetimes.

(a) Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.

A sugar can have ... (a) H covalently bound to the C of a C=O group. (b) a C atom that is covalently bound to three H atoms. (c) the formula C5H8O5. (d) Both (a) and (c). (e) Both (b) and (c).

(a) H covalently bound to the C of a C=O group. This occurs in linear aldoses such as glucose.

Which feature is shared by all monosaccharides? (a) In their linear forms, they all contain a carbonyl and several hydroxyl functional groups. (b) They are all pentoses. (c) In their linear forms, they all contain a carboxyl and several hydroxyl functional groups. (d) They all contain more than one sugar.

(a) In their linear forms, they all contain a carbonyl and several hydroxyl functional groups. Note that in aqueous solution monosaccharides tend to exist in cyclic, not linear, forms.

Cellulose is ... (a) Made with glucose that has the beta ring form. (b) A component of crab shells. (c) The third most abundant organic compound in the world. (d) A branching polymer. (e) All of the above.

(a) Made with glucose that has the beta ring form. That's what makes it impossible for humans to digest cellulose. Fungi, plants, and many microbes can digest it, though.

Which of these is a source of lactose? (a) Milk (b) Potatoes (c) Sugar cane (d) Sugar beets (e) Starch

(a) Milk Lactose is the sugar found in milk.

A cotton shirt is chemically most similar to a ... (a) Sugar cube. (b) Slice of ham. (c) Pat of butter. (d) DNA double helix. (e) Fingernail.

(a) Sugar cube. Both cotton and a sugar cube are carbohydrates, made of sugars.

What is the major structural difference between starch and glycogen? (a) The amount of branching that occurs in the molecule (b) Whether glucose is in the α or β form (c) The types of monosaccharide subunits in the molecules (d) The type of glycosidic linkages in the molecule

(a) The amount of branching that occurs in the molecule

How do the α and β forms of glucose differ? (a) Their ring structures differ in the location of a hydroxyl group. (b) Their linear structures differ in the location of a hydroxyl group. (c) The α form can be involved in 1,4- and 1,6-glycosidic linkages; the β form can participate only in 1,4 linkages. (d) The oxygen atom inside the ring is located in a different position.

(a) Their ring structures differ in the location of a hydroxyl group.

Which of the following structural features is common to cellulose, chitin, and peptidoglycan? (a) They can all form bonds between polymer chains that create parallel strands. (b) They are all composed of glucose in either the α or β form. (c) They are all composed of highly branched fibers. (d) They all contain peptide bonds.

(a) They can all form bonds between polymer chains that create parallel strands.

Cellulose is _____. (a) A monomer of starch. (b) A major structural component of plant cell walls (c) A polymer composed of fructose monomers (d) Used by plants to make glycogen (e) A storage polysaccharide for energy in plant cells

(b) A major structural component of plant cell walls

Glycogen is _____. (a) A source of saturated fat (b) A polysaccharide found in animals (c) A transport protein that carries oxygen (d) A polysaccharide found in plant cell walls (e) The form in which plants store sugars

(b) A polysaccharide found in animals Animals store energy in the form of glycogen.

Which of the following polysaccharides composes the cell wall of fungi? (a) Peptidoglycan (b) Chitin (c) Starch (d) Glycogen

(b) Chitin Chitin is a structural polysaccharide that forms the cell wall of fungi and is also found in the exoskeleton of insects.

The bond that joins two monosaccharides into a disaccharide is a(n) _____. (a) Van der Waals bond (b) Glycosidic bond (c) Ionic bond (d) Hydrogen bond

(b) Glycosidic bond The glycosidic bond is a covalent bond that joins two sugars together via a condensation reaction.

The _____ functional group can always be found in a carbohydrate molecule. (a) Amino (b) Hydroxyl (c) Phosphate (d) Water

(b) Hydroxyl Carbohydrates are aldehydes or ketones with multiple hydroxyl groups.

Glycogen ... (a) Contains several kinds of sugars. (b) Occurs in animal cells and has branches. (c) Is stronger, weight for weight, than steel. (d) Occurs in chloroplasts and stores energy. (e) None of the above.

(b) Occurs in animal cells and has branches. This branched polymer is the main energy-storing carbohydrate in animals and humans.

Which of the following polysaccharides contains peptide bonds? (a) Starch (b) Peptidoglycan (c) Glycogen (d) Chitin

(b) Peptidoglycan Peptidoglycan is a structural polysaccharide found in bacterial cell walls. The sugars are modified with amino acids that can form peptide bonds to covalently link adjacent strands.

Which statement best summarizes a key difference in the structure of polysaccharides that function in energy storage versus those used in structural support? (a) Polysaccharides that function in energy storage are built from β glycosidic linkages, whereas polysaccharides used in structural support form straight chains that bond with adjacent chains. (b) Polysaccharides that function in energy storage are built from α glycosidic linkages, whereas polysaccharides used in structural support form straight chains that bond with adjacent chains. (c) Polysaccharides that function in energy storage form straight chains that bond with adjacent chains, whereas polysaccharides used in structural support are built from α glycosidic linkages. (d) Polysaccharides that function in energy storage are built from α glycosidic linkages, whereas polysaccharides used in structural support form helical chains that are highly branched.

(b) Polysaccharides that function in energy storage are built from α glycosidic linkages, whereas polysaccharides used in structural support form straight chains that bond with adjacent chains. α linkages are readily hydrolyzed to release glucose; straight chains bond to adjacent chains to form tough fibers.

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? (a) Chitin (b) Starch (c) Starch and chitin only (d) Cellulose (e) Starch, cellulose, and chitin

(b) Starch

What is the difference between an aldose sugar and a ketose sugar? (a) The position of the hydroxyl groups (b) The position of the carbonyl group (c) The number of carbons (d) One is a ring form, the other is a linear chain

(b) The position of the carbonyl group

Which fact is most important in explaining why cellulose is a better structural material than starch? (a) Polymers made of fructose are stronger than polymers made of glucose. (b) Branched polymers can form more hydrogen bonds than unbranched polymers. (c) Alpha-linkages make it easier for the polymer to coil into a helix. (d) C-C links are stronger than C-O-C links. (e) Links between alpha glucoses are stronger than links between beta glucoses.

(c) Alpha-linkages make it easier for the polymer to coil into a helix. The alpha links let starch coil into compact helices that pack into dense granules. For structural use, you want polymers that stretch out straight and form cables, as in beta-linked cellulose.

Cells of which organisms lack cell walls? (a) Plants (b) Fungi (c) Animals (d) Bacteria

(c) Animals Animal cells do not have a cell wall external to the plasma membrane.

Starch and cellulose _____. (a) Are cis-trans isomers of each other (b) Can be digested by humans (c) Are polymers of glucose (d) Are structural components of the plant cell wall (e) Are used for energy storage in plants

(c) Are polymers of glucose

What type of bond is formed between two sugars in a disaccharide? (a) Peptide bond (b) Hydrogen bond (c) Glycosidic linkage (d) Phosphodiester bond

(c) Glycosidic linkage

A molecule has the formula C n H2 n O n . What else does it need to be an unmodified monosaccharide? (a) Nothing. (b) A carboxyl group. (c) O bound to every C. (d) At least 5 carbon atoms. (e) Both (b) and (c).

(c) O bound to every C. If a monosaccharide has C without O attached, it's been modified.

What is the LEAST that two molecules can differ, and still be called different kinds of sugars? (a) The number of C atoms differs. (b) One is a ring, the other is linear. (c) The orientation of an OH group differs. (d) The location of the carbonyl group differs. (e) None of the above.

(c) The orientation of an OH group differs. In the open-chain form, two sugars may differ in the orientation (right or left) of just one OH group.

Which of the following do starch and cellulose have in common? (a) The type of glycosidic linkage used (b) Their main function in plants (c) The size of their monosaccharide subunits (d) The amount of hydrogen bonding that occurs between parallel strand

(c) The size of their monosaccharide subunits

Which of the following linkages would you expect to find at a branch point in glycogen or amylopectin? (a) α-1,4-glycosidic linkage (b) β-1,6-glycosidic linkage (c) α-1,6-glycosidic linkage (d) β-1,4-glycosidic linkage

(c) α-1,6-glycosidic linkage

Unmodified sugars (those with the formula C n H2 n O n ) can have ... (a) H covalently bound to the C of a C=O group. (b) A C atom that is covalently bound to three H atoms. (c) The formula C3H6O3. (d) Both (a) and (c). (e) Both (b) and (c).

(d) Both (a) and (c). The best choice! Glucose is one of many sugars that have H bound to C=O; they're called aldoses. The simplest sugar has the formula C3H6O3.

The alpha and beta forms of glucose, found in starch and cellulose, differ in ... (a) Whether the molecule is a ring or an open chain. (b) Whether the ring contains five or six C atoms. (c) Whether the first C atom is bound to one or two O atoms. (d) How one of the -OH groups is oriented. (e) None of the above.

(d) How one of the -OH groups is oriented. One particular -OH group points to one side of the ring in alpha glucose; the other side in beta glucose.

glucose + glucose —> _____ by _____. (a) Lactose + water ... hydrolysis (b) Sucrose + water ... dehydration synthesis (c) Starch + water ... dehydration synthesis (d) Cellulose + water ... hydrolysis (d) Maltose + water ... dehydration

(d) Maltose + water ... dehydration Maltose is the disaccharide formed when two glucose molecules are linked by dehydration synthesis.

A sugar that has the chemical formula C5H10O5 would be characterized as a(n) _____. (a) Hexose (b) Triose (c) Oligosaccharide (d) Pentose

(d) Pentose Pentose is the general term for a five carbon sugar such as ribose.

Which statement is true of sucrose? (a) It's a disaccharide. (b) It contains glucose. (c) It's table sugar. (d) Both (a) and (c). (e) - (a), (b), and (c).

(e) - (a), (b), and (c) We use sucrose as our table sugar because plants make plenty of it. They use it as their main circulating fuel, and sugar beets and sugar cane store a lot of it. It's a disaccharide made of glucose and fructose.

Fat

- Functions mainly as energy-storage molecules but can also be part of the cell membrane. Monomer unit consists of fatty acids and polymer units consist of triglycerides. Also called lipids.

The ionized or dissociated carboxyl group may be written as _____________.

-COO -

What suffix is commonly found on the end of sugar names?

-ose

How many hydrogen atoms can be attached to carbon B

1 because it already has three

How does DNA differ from RNA? a) DNA is larger b) one of their nitrogenous bases is different. c) they contain different sugars d) DNA consists of two strands in a double helix e) All of the above are differences

All of the above are differences

How many hydrogen atoms can be attached to carbonA

3 because it already has one

Which of the functional groups behaves as a base?

A

Carbon atoms are the most versatile building blocks of the molecules used by living organisms because _____________.

each carbon atom can form up to four covalent bonds with a wide variety of bond angles.

Polysaccharide

A carbohydrate polymer consisting of hundreds to thousands of monosaccharides (sugars) linked by dehydration synthesis

Carbon skeleton

A chain of carbon atoms that forms the structural backbone of an organic molecule

Hydrocarbon

A chemical compound composed only of the elements carbon and hydrogen

Organic compound

A chemical compound containing the element carbon and usually synthesized by cells

Hydrolysis

A chemical process in which polymers are broken down by the chemical addition of water molecules to the bonds linking their monomers; an essential part of digestion

Dehydration reaction

A chemical process in which two molecules become covalently bonded to each other with the removal of a water molecule. Also called condensation.

Monomer

A chemical subunit that serves as a building block of a polymer

What is a disaccharide, Name two common disaccharides?

A disaccharide forms when two monosaccharides are joined by dehydration synthesis. Sucrose, lactose, andmaltose are common disaccharides.

Deoxyribonucleic acid (DNA) ‐

A double‐stranded helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T). Capable of replicating, is an organism's genetic material.

Macromolecule

A giant molecule in a living organism formed by the joining of smaller molecules: a protein, carbohydrate, or nucleic acid

Polymer

A large molecule consisting of many identical or similar molecular units, called monomers, covalently joined together in a chain

Cellulose

A large polysaccharide composed of many glucose monomers linked into cable‐like fibrils that provide structural support in plant cell walls

Phospholipid

A lipid made up of glycerol joined to two fatty acids and a phosphate group, giving the molecule a nonpolar hydrophobic tail and a polar hydrophilic head. Phospholipids form bilayers that function as biological membranes

Polypeptide

A polymer (chain) of amino acids linked by peptide bonds

Enzyme

A protein (or RNA molecule) that serves as a biological catalyst, changing the rate of a chemical reaction without itself being changed into a different molecule in the process

Cholesterol

A steroid that is an important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids such as hormones

Starch

A storage polysaccharide found in the roots of plants and certain other cells; a polymer of glucose

Chitin

A structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods

Disaccharide

A sugar molecule consisting of two monosaccharides linked by a dehydration reaction

Steroid

A type of lipid whose carbon skeleton is in the form of four fused rings with various chemical groups attached; examples are cholesterol, testosterone, and estrogen

Ribonucleic acid (RNA)

A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), guanine (G), cytosine (C ), and uracil (U); usually single‐stranded; functions in protein synthesis and as the genome of some viruses

Which one of these is an amino group

A) NH2

Based on the way nitrogen bases pair, you would expect the percentage of _____to be equal to the percentage of ______. a) A...T b) A...G c) T...G d) A...C e) T...C

A...T

Functional groups

An assemblage of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions

Glycogen

An extensively branched polysaccharide of many glucose monomers; serves as an energy‐storage molecule in liver and muscle cells; the animal equivalent of starch

Lipid

An organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic. These molecules include fats, phospholipids, and steroids and are insoluble in water

Amine

An organic compound with one or more amino groups

Amino acid

An organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins

Nucleotide

An organic monomer consisting of a five‐carbon sugar covalently bonded to a nitrogenous base and a phosphate group. These molecules are the building blocks of nucleic acids.

Once all the helices and sheets are coiled, folded, and locked into place, the polypeptide takes on a distinct three-dimensional shape. This is the third or tertiary level of protein structure: the overall conformation or three-dimensional shape of a protein. To think about protein shapes, imagine that I have a big barrel of clay and I ask everyone in the class to grab a lump and put it on their desk.

At first glance, all the lumps look similar; they are all blobby lumps of clay. But closer observation reveals that every lump of clay is unique. Some are taller or fatter, some have bumps and grooves that others lack. Similarly, while most proteins look basically like round-ish blobs, each one has small differences in their structure. And these differences in shape are vital to the job a protein performs. That is, form follows function. Change a protein's shape in the slightest (by, say, cutting off a lump) and the protein may not be able to perform its job within the cell.

Which of these is a phosphate group

B

Which of these groups plays a major role in energy transfer?

B, ATP is a phosphate

Most proteins are folded into a complex globular shape. Each protein molecule consists of one or more chains of amino acid monomers. The amino acids are linked by peptide bonds, so a protein polymer is often called a polypeptide.

Because they are so complicated, proteins are usually described in terms of four levels of structure.

This topic introduces the framework of biological macromolecules that are proteins and nucleic acids.

Both consist predominantly of carbon atoms bonded to other carbon atoms or to oxygen, hydrogen, phosphorus, nitrogen, or sulfur.

To understand the secondary level of protein structure, imagine that you are an alien seeing a roomful of human beings for the first time. The first thing you might notice is that every person has a unique shape.

But you would quickly start to notice similarities in the shapes. Every person, for example, has a rectangular body with a spherical blob at the top and four long limbs sticking out.

Which of these is a carbonyl group

C

Select the hydrocarbon from the following choices: a) C3H8 b) CO2 c) C6H12O6 d) H2CO3 e) CCL2F2

C3H8

Which is an organic molecule: a) Ne b)O2 c) CH4 d) NaCl e) H20

CH4

- range from small sugars to large starches - hydrophilic - main fuel molecules for cellular work

Carbohydrates

name the four main classes of biological (organic) molecules [[abc order]]:

Carbohydrates, Lipids, Nucleic acids, and Proteins

chain of carbon atoms; form skeletons of most organic molecules

Carbon skeletons

What types of atoms make up carbohydrates?

Carbon, hydrogen, & oxygen

Which of these is a polysaccharide? (a) Cellulose (b) Galactose (c) Glucose (d) Sucrose (e) Lactose

Cellulose is a carbohydrate composed of many monomers.

What are the complex carbohydrates?

Starch, Glycogen, and Cellulose

Which of these functional groups is characteristic of alcohol?

D

Which of these is a hydroxyl group

D

A shortage of phosphorous in the soil would make it especially difficult for a plant to manufacture_______.

DNA

what are the two types of nucleic acids?

DNA and RNA

Which of these is a carboxyl group

F

The fourth level of protein structure describes interactions among different polypeptides. Some complex proteins are composed of more than one polypeptide chain that bond together to form a sort of super protein.

For example, the blood protein hemoglobin is composed of four different polypeptide chains that interlock. Another example is the molecular machine known as DNA polymerase, the enzyme that builds new DNA molecules during DNA replication. DNA polymerase is actually a large complex made up of a number of different polypeptide chains joined together. Not all proteins have quaternary structure, but the big ones usually do.

-groupings of atoms that are involved in chemical reactions -give organic molecules particular (predictable) properties

Functional groups

Name two common monosaccharides and give the molecular formula for each

Glucose and fructose, both have the molecular formula C6H12O6

composed of only C and H; nonpolar

Hydrocarbon

Are carbohydrates generally hydrophilic or hydrophobic

Hydrophilic (due to the many -OH groups)

What two functional groups are found in monosaccharides?

Hydroxyl and carbonyl

In each of these examples, the shape or structure of a protein is the key to understanding how it works. How can the shape of a protein be so important? Let's try an analogy. Pliers are one of the most commonly used tools for extending the power and grip of your hand. Most people have used pliers to accomplish a specific task, such as cracking a nut, removing a bolt, bending wire, cutting wire, and so on.

In each case, the moveable jaws of the pliers are shaped for specific tasks. Using them for a different duty sometimes leads to frustration. For example, you can't remove a bolt with a pair of needle-nosed pliers. Shape is important to a tool's function, and the same is true for proteins. Each of the thousands of different kinds of proteins in your body has its own unique shape.

Proteins-- the purple blobs in this closeup of an animal cell-- are the most complicated molecules known. A cell contains thousands of kinds of proteins, which carry out a variety of functions.

In most cases, a protein's function depends on its complex three-dimensional structure.

molecules with same molecular formula but different structures

Isomers

Generally, animals cannot digest the linkages between the glucose molecules in cellulose. How then do cows get enough nutrients form eating grass? a) They have to eat a lot of it. b) Microorganisms in their digestive tracts hydrolyze the cellulose to glucose. c) Cows and other herbivores are exceptions and make some cellulose-digesting enzymes. d) The flat teeth and strong stomach of the herbivores break the cellulose fibers so the cows get enough nutrition from the cell contents. e) All of the above

Microorganisms in their digestive tracts hydrolyze the cellulose to glucose

What is the simplest type of carbohydrate?

Monosaccharides

How do these hydrocarbons differ

One of these hydrocarbons has a double bond.

How do these hydrocarbons differ

One of these hydrocarbons has a ring structure.

How do these hydrocarbons differ

One of these hydrocarbons is branched

What are functional groups?

Organic molecules contain groups of atoms which give the molecule certain chemical characteristics, so that they function in specific ways during chemical reactions. an atom or group of atoms that bestow some characteristic property to a molecule so that any molecule with the same group will react chemically in a similar fashion.

Saturated

Pertaining to fats and fatty acids whose hydrocarbon chains contain the maximum number of hydrogens and therefore have no double covalent bonds. If a fat is in this category it will solidify at room temperature

Unsaturated

Pertaining to fats and fatty acids whose hydrocarbon chains lack the maximum number of hydrogen atoms and therefore have one or more double covalent bonds. If a fat is in this category it will not solidify at room temperature

Proteins have the most diverse and complex architecture of any of the biological macromolecules. You have tens of thousands of different proteins in your body that have diverse structures and perform diverse jobs. Proteins are the worker bees of your body. They take part in nearly every activity of an organism.

Proteins play a role in structural support (as in cartilage), transport (such as hemoglobin), hormones (like insulin), immunity (your antibodies), movement (as with muscle proteins), and as enzymes that keep thousands of different chemical reactions running inside all cells.

Which of these is found in amines? a) R-COOH b) R-COH c) R-OH d) R-NH2 e) R-PO4

R-NH2

Which of these is found in amino acids? a) R-PO4 b) R-COH c) R-OH d) R-NH2 e) -C=O

R-NH2

RNA polymer. RNA looks a lot like DNA, except it is typically single-stranded, contains a different sugar (called ribose), and has the base uracil (U) instead of thymine (T).

RNA is copied from part of a DNA molecule, so it is shorter than DNA-- dozens to thousands of nucleotides.

Nutritionally, saturated triglycerides are considered to be less healthful than unsaturated. What is one major difference between them? a) Saturated triglycerides are fats; unsaturated are carbohydrates b) Saturated triglycerides have more hydrogens than unsaturated c) Saturated triglycerides have more double bonds than unsaturated d) Saturated triglycerides are liquid at room temperature e) All of the above

Saturated triglycerides have more hydrogens than unsaturated

main function of fats

energy storage

If you look at many proteins, you will similarly notice certain common structural elements. The two most common are called an alpha helix and a beta sheet. An alpha helix is a region of a protein that is twisted into a tight spiral.

The coils of the helix are held together by hydrogen bonds between nearby amino acids. Other regions of a protein fold up like a paper fan. This type of structure is referred to as a beta sheet. The alpha helices and the beta sheets together comprise the secondary structure of a protein. A given protein might have three alpha helices and four beta sheets, while another has eight and two, and so on. Most proteins have at least some of each.

Peptide bond

The covalent linkage between two amino acid units in a polypeptide; formed by a dehydration reaction

four levels of protein structure:

The first level is the sequence of amino acids. The second level is the formation of alpha helices and beta sheets. The third level is the folding of a polypeptide into its final threedimensional shape. The fourth level is the joining of more than one chain to form a larger complex.

Double helix

The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape

defensive protein

The immune system makes defensive proteins called antibodies that bind to invaders (such as the virus shown here) and mark the foreign objects for destruction.

-consist mainly of C and H linked by NONPOLAR covalent bonds -grouped together because they are hydrophilic -do not dissolve in water

lipids

The first or primary level of protein structure is simply the linear sequence of amino acids that are strung together to make the protein chain. Every protein has a unique amino acid sequence. Just as you can build thousands of words using just 26 letters of the English alphabet, a huge variety of proteins can be constructed from 20 different amino acids. Just like English letters have different properties—such as consonants vs. vowels—so do amino acids.

The properties of an individual amino acid lay in its side chain that branches off of the carbon backbone. The side chain can also be called the R group or radical group

Monosaccharide

The simplest carbohydrate; a simple sugar with a molecular formula that is generally some multiple of CH2O. These molecules are the building blocks of disaccharides and polysaccharides

DNA normally consists of two strands of nucleotides that twist around one another, forming the famous double helix.

The strands are held together by hydrogen bonds between pairs of nitrogenous bases. The base A always pairs with T, and C always pairs with G.

How does the number of H atoms in a carbohydrate compare to the number of oxygen atoms?

There are twice as many hydrogens as oxygens

Although cells are 70-95% water, the rest consists mostly of carbon-based compounds also known as organic compounds. Carbon is unparalleled in its ability to form large, complex, and diverse molecules.

There is an enormous assemblage of organic molecules synthesized and used by living things referred to as biological macromolecules. These biological macromolecules can be divided into four categories: carbohydrates, lipids, proteins and nucleic acids.

How are monosaccharides used in a cell?

They supply energy for cellular work. They also serve as raw materials for building other organic molecules.

What is an enantiomere?

They're mirror images, and that makes them enantiomers.

If even one amino acid is out of order it can make the entire protein non-functioning. However, let me point out that some amino acids can be substituted for others without altering the function of a protein. Let's go back to the word analogy for a second. If you change just one letter in some words you can completely change the meaning. For example, changing one letter in the word "ship" can produce a complete different word like "shop"—very different meanings, right? Other words, however, are not as susceptible to single changes. If you change a letter around, they may be misspelled, but their meaning may not be changed.

To recap, the primary structure of a protein is simply the list of amino acids in their proper order.

Each protein has a unique primary structure— a particular number and sequence of amino acids making up the polypeptide chain.

Twenty different amino acids are used to build proteins. Theoretically, the various amino acids could be linked in almost any sequence, forming an almost infinite variety of different proteins.

Cholesterol belongs to which class of molecules?

lipids

drag & drop dehydration synthesis

Use the simulation to combine two glucose molecules to form maltose, a disaccharide. The reaction that forms the disaccharide is called dehydration synthesis. Now, separate the disaccharide by hydrolysis. These reactions are described in your textbook. Now try to build a fructose molecule and then a sucrose molecule.

A glucose molecule is to starch as ________. a) a steroid is to a lipid b) a protein is to a amino acid c) a nucleic acid is to a polypeptide d) a nucleotide is to a nucleic acid e) an amino acid is to a nucleic acid

a nucleotide is to a nucleic acid.

In a hydrolysis reaction, ______. In this process, water is______. a) a polymer breaks up to form monomers...consumed b) a monomer breaks up to form polymers...produced c) monomers are assembled to produce a polymer...consumed d) monomers are assembled to produce a polymer...produced e) a polymer breaks up to form monomers...produced

a polymer breaks up to form monomers...consumed

enzyme

a protein that changes the rate of a chemical reaction without itself being changed into a different molecule in the process. Enzymes promote and regulate virtually all chemical reactions in cells.

abbreviated G, A, C, or T. Like letters in a sentence, the sequence of nucleotides in a nucleic acid carries information. The DNA of every organism has a unique nucleotide sequence.

a tiny segment of DNA, which may be millions of nucleotides in length.

Carboxyl is to __________ as ___________ is to base. a) acid...carbonyl b) base...carbonyl c) acid...amino d) base...amino e) None of these choices is correct

acid...amino

During hydrolysis, energy and enzymes are required and water is....

added

A, T, C, and G, stand for

adenine, thymine, cytosine, and guanine

Hydroxyl is to_____ as _______ is to amine. a) carbonyl...carboxyl b) ketone...amino c) carbon...nitrogen d) aldehyde...ketone e) alcohol...amino

alcohol...amino

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the protein shape? a) denaturing the protein b) making changes to the concentration of salt in the environment c) heating the protein d) making changes to the pH of the environment e) All of the above

all of the above

Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they________. a) all share the same functional group: a hydroxyl b) are soluble in water c) are soluble in nonpolar solvents d) all contain a carbonyl group e) increase the acidity of solutions

all share the same functional group: a hydroxyl

Protein molecules are polymers of _______.

amino acid molecules

The "primary structure" of a protein refers to the number of sequence of _______ ________.

amino acids

Each amino acid contains:

an amino groups, a carboxyl group, and an R group

Although the structures of the functional groups important to life vary in chemical structure, they share one thing in common: They________. [[just type the answer not the letter]] a) all contain oxygen b) all have at least one double bond c) cause the carbon to which they are attached to become an asymmetric carbon, and they convert the molecule into an isomer d) unite the skeleton into a closed ring e) are all hydrophilic and increase the organic compound's water solubility

are all hydrophilic and increase the organic compound's water solubility

Lipids differ from other large biological molecules in that they______________. a) are much larger b) are not truly polymers c) do not have special shapes d) do not contain carbon e) contain no nitrogen atoms

are not truly polymers

Carbohydrates are mainly used in our bodies _____.

as fuel

Which of these has the highest sweetness? a) lactose b) glucose c) sucrose d) maltose e) aspartame

aspartame

gene regulatory proteins

bind to DNA in particular locations and control whether or not certain genes will be read. This allows cells to become specialized for different functions and respond to changes in their surroundings.

receptor molecules

bind to signal molecules and can then emit second messengers which trigger changes inside a cell. Receptors are thus important links in the system of communication among cells. Some signal molecules, such as hormones, are also proteins.

The four main categories of macromolecules in a cell are_____. [[name in abc order; include the word and.]]

carbohydrates, lipids, nucleic acids, and proteins

Which element is most particularly associated with organic chemistry?

carbon

Citric acid makes lemons taste sour. Which functional group would cause a molecule like citric acid to be acidic?

carboxyl

transport protein

carry molecules from place to place. The example shown here allows certain solute molecules to enter the cell. Hemoglobin is the transport protein that carries oxygen in the blood.

-most of plant in made of molecules of cellulose -found in plants cell walls(protection and stiffness) -consist of glucose monomers -forms cable-like fibers

cellulose

___________ is a polysaccharide found in plant cell walls.

cellulose

Hydrogenated vegetable oils are more like animal fats than are other plant oils. Because they __________ than other plant oils, they can contribute to cardiovascular disease. a) contain fewer double bonds b) contain more double bonds c) contain more sodium d) are less soluble in water e) contain less hydrogen

contain fewer double bonds

name the different kinds of proteins

contractile, defensive, enzymes, structural, signal, storage, and transport proteins

The peptide bond is a _________ bond.

covalent

guanine always pairs with

cytosine

cells link monomers to form polymers by a process called...

dehydration reaction

What is the process by which cells link monomers together to form polymers?

dehydration synthesis

process by which a protein unravels, losing its specific shape and thus its specific function

denaturation

DNA spelled out is

deoxyribonucleic acids

sensory protein

detect environmental changes such as light, and respond by emitting or producing signals that call for a response.

monosaccharides can join to form _________.

disaccharides

Which one of the following is NOT a function of carbohydrates (as a class). a) structural support b) energy storage c) energy source d) enzymatic catalysis e) All are carbohydrate functions.

enzymatic catalysis

catalyst that speeds up chemical reactions

enzymes

also called triglycerides

fats

Name the four types of lipids [[in abc order]]

fats, phospholipids, steroids, and waxes

These four levels are known as primary, secondary, tertiary, and quaternary.

first, second, third or fourth level of protein structure.

a part of a DNA sequence that programs the amino acid sequence of proteins; works through RNA

genes

-found in animal cells -store excess sugar in muscles and liver cells -consists of glucose monomers -more highly branched than starch

glycogen

A polysaccharide that we use for storing energy in our muscles an livers is______.

glycogen

structural proteins

have many functions. Like tent poles and ropes, they shape cells and anchor cell parts. They may serve as tracks along which cell parts can move. They bind cells together, making organized units such as muscles, ligaments, and the tendons that bind muscles to bones. The silk of spiders and the hair of mammals are also structural proteins.

How does a protein's quaternary structure differ from other level of protein structure? a) involves two or more polypeptide chains b) it takes the form of an alpha helix c) it is described by the sequence of amino acids in a polypeptide chain. d) it depends on interactions among a polypeptide's R groups. e) it takes the form of a pleated sheet.

it involves two or more polypeptide chains

Manufacturers make vegetable oils solid or semisolid by adding __________.

hydrogens

polymers are broken down to monomers by the reverse process...

hydrolysis

compounds that do not mix with water.

hydrophobic

what two groups do sugars contain?

hydroxyl groups and a carboxyl group

signal proteins

include hormonal proteins that help coordinate an organism's activities by acting as signals between cells. For example, insulin, a hormonal protein secreted by the pancreas, signals an animal's cells to take in and use sugar. The hormone receptor is also a protein.

Superimposed on primary and secondary structure is tertiary structure,

irregular loops and folds that give the protein its overall three-dimensional shape.

gigantic molecules

macromolecules

cells make macromolecules by joining similar, smaller, organic molecules called...

monomers

single-unit sugars

monosaccharides

monomers of nucleic acids

nucleotides

DNA polymer

one of two twisted strands that make up a DNA molecule. Cells make nucleic acid polymers by linking together four kinds of monomers called nucleotides. Each nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogen-containing base-

carbon based; at least one H atom

organic compounds

proteins are made from amino acids linked by ____________ bonds

peptide

covalent bonds between amino acid monomers

peptide bonds

The lipids that form the main structural component of cell membranes are________.

phospholipids

____________are a major component of cell membranes

phospholipids

Cellulose is a ______ made of many _______.

polymer...glucose molecules

monomers form chains called...

polymers

a chain of amino acids linked by peptide bonds

polypeptides

starch and glycogen are both ___________; store sugar for later use

polysaccharides

Which of the following would probably NOT be affected when a protein is denatured? a) primary structure b) secondary structure c) hydrogen bonds d) tertiary structure e) All of the above must be affected for the protein to be denatured

primary structure

the unique sequence of amino acids forming its polypeptide chains; determined by inherited genetic information

primary structure

name the four levels of structure [[proteins]]

primary structure, secondary structure, tertiary structure, and quaternary structure

a polymer constructed from amino acid monomers

protein

results from association of two or more polypeptide chains

quaternary structure

During dehydration reaction, energy and enzymes are required and water is

released

irregular loops and folds that give the protein its overall three-dimensional shape.

results from the combination of two or more polypeptide subunits.

RNA spelled out is

ribonucleic acid

most monosaccharide occur as _______ structures

ring

lack of double bonds; do not bond to maximum number of H; pack tightly together; contributes to cardiovascular disease

saturated fats

The alpha helix and pleated sheet represent which level of protein structure?

secondary structure

the coiling or folding of the chain, stabilized by hydrogen bonding

secondary structure

-found in plant cells -store excess sugar -consists of glucose monomers -a branched looping chain

starch

In what polysaccharide for do plants store sugar to be available later for energy?

starch

The complex carbohydrate that you are most likely to have eaten recently is__________.

starch

Storage Proteins

stockpile building components that cells can use to make other proteins. Storage proteins in seeds provide raw materials used by the developing plant-- unless an animal eats them first!

The ovalbumin in egg white can be classified as which type of protein?

storage

The overall three-dimension shape of a polypeptide is called the ___________.

tertiary structure

the overall three dimensional shape of a polypeptide; globular or fibrous; results form interaction of R groups

tertiary structure

One characteristic shared by sucrose and maltose is____________.

they are all disaccharides

Which of the following do nucleic acids and proteins have in common? a) they are both made of amino acids b) Their structures contain sugars c) They are hydrophobic d) They are large polymers e) They each consist of four basic kinds of subunits.

they are large polymers

adenine always pairs with

thymine

A fatty acid containing at least two double bonds is called _______.

unsaturated

contain double bonds; have kinks; prevents bonding to maximum number of H

unsaturated fats

__________form waterproof coatings

waxes

In most proteins, parts of the polypeptide chain are coiled or folded, forming twists and corrugations. This is secondary structure. The turns and folds of secondary structure contribute to the protein's overall shape. One kind of secondary structure is the alpha helix,

where the chain twists. Another is the pleated sheet, where the chain folds back on itself or where two regions of the chain lie parallel to one another.

Amino acids are joined together by peptide bonds to make polypeptides.

yes that

Denaturation

‐ A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature. Also refers to the separation of the two strands of DNA double helix, caused by similar factors

Describe 6 functions proteins may perform.

• Enzymes - Control chemical reactions • Structural - Forming structures such as hair and tendons • Movement - Such as proteins in muscles • Transport - Hemoglobin carries O2 in the blood • Communication - Signal proteins and some hormones • Defense - Antibodies that defend the body against microorganisms • Storage - Such as albumen (the whites) in eggs