Chapter 3 Practice Problems

Complete the following paragraph to describe synthesis and degradation reactions: Large biomolecules, or ___________, are comprised of smaller subunits called _____________. These subunits attach together to build biomolecules through ______________ reactions. This type of reaction involves the ___________ of water as ___________ are linked together and __________ built. Biomolecules are broken down into their subunits through ____________ reactions. This type of reaction involves the _________ of water as polymers are broken down into monomers. These synthesis and degradation processes are catalyzed by ______________.

Large biomolecules, or polymers, are comprised of smaller subunits called monomers. These subunits attach together to build biomolecules through dehydration reactions. This type of reaction involves the formation of water as monomers are linked together and polymers built. Biomolecules are broken down into their subunits through hydrolysis reactions. This type of reaction involves the addition of water as polymers are broken down into monomers. These synthesis and degradation processes are catalyzed by enzymes.

Lipids Complete the following paragraph to describe the important functions of lipids: Lipids are ___________ in water due to the _____________ nature of their long hydrocarbon chains. In animals, ________ provides vital long-term energy storage. In plants, _________ provide vital long-term energy storage. Within all organisms, _____________ comprise the bulk of the plasma membrane, allowing it the many properties that it needs to function. Embedded within the plasma membrane are ___________, which provide cell to cell communication and contribute to plasma membrane flexibility. Many organisms, including plants, have slick coverings made of ___________, which provide both protection and waterproofing.

Lipids are insoluble in water due to the nonpolar nature of their long hydrocarbon chains. In animals, fats provides vital long-term energy storage. In plants, oils provide vital long-term energy storage. Within all organisms, phospholipids comprise the bulk of the plasma membrane, allowing it the many properties that it needs to function. Embedded within the plasma membrane are steroids, which provide cell to cell communication and contribute to plasma membrane flexibility. Many organisms, including plants, have slick coverings made of waxes, which provide both protection and waterproofing.

cellulose, starch, and glycogen are composed of what?

all are composed of multiple glucose molecules

carbohydrates: monomer and polymer lipids: monomer and polymer proteins: monomer and polymer nucleic acids: monomer and polymer

carbohydrates: monomer- monosaccharide polymer- polysaccharide lipids: monomer- glycerol and 3 fatty acids polymer: does not form a polymer proteins: monomer- amino acids polymer- polypeptides nucleic acids: monomer- nucleotides polymer- DNA and RNA

Phospholipids: comprised of _______________ and ____________ have a ___________ and a ____________ and make up the ________________

comprised of 2 fatty acid tails and a glycerol phosphate head have a hydrophilic head and a hydrophobic tail and make up plasma membrane

Steroids: contain no ___________________ what 3 things are examples of steroids? composed of a ___________ of _____________ provide _____________ to the ___________

contain no fatty acids cholesterol, testosterone, and estrogen are examples composed of a carbon skeleton of four fused rings provides flexibility to the plasma membrane

Fats and oils: function as ______________ comprised of ___________ and ____________

function as long term energy storage comprised of glycerol and 3 fatty

amino functional groups are present in what?

present in all amino acids R, N-H, N-H

carboxyl functional group is present in what?

present in fatty acids and amino acids R, C=O, C-OH

phosphate groups are present in what?

present in phospholipids and nucleotides

sulfhydryl groups are present in what?

present in some amino acids R-SH

carbonyl functional groups are present in what?

present in sugars R, C=O, C-H

hydroxyl function groups are present in what?

present in sugars and amino acids R-OH

Functions of lipids:

- comprise the P.M. of cells and gives them flexibility -provide light weight long term energy storage -provide a protective and waterproof covering for plants -provide insulation from cold and injury -comprise vital hormones and chemical signalers

glycogen

-energy storage for animals -highly branched structure

Starch

-energy storage for plants -branched (amylopectin) or long chained (amylose) in structure

Cellulose

-structural support for plants -long chains with every other glucose flipped -structure allows for hydrogen bonding and greater strength

Complete the following paragraph to describe the categories of carbohydrates: Carbohydrates exist as either monomers or ______________, long chains of monomers bonded together. Single monomers are called __________ and include molecules like glucose, which are typically used for ______________ or to help build the backbone of nucleotides that make up RNA and DNA. Combinations of two monomers are called ___________ and include molecules like ____________, which are typically ___________ and can be metabolized into ___________. Groups of three or more monomers are called _______________ and include ____________ and other molecules typically used for _______________ and structural support.

Carbohydrates exist as either monomers or polymers, long chains of monomers bonded together. Single monomers are called monosaccharides and include molecules like glucose, which are typically used for immediate energy or to help build the backbone of nucleotides that make up RNA and DNA. Combinations of two monomers are called disaccharides and include molecules like maltose, which are typically transported and can be metabolized into fat. Groups of three or more monomers are called polysaccharides and include starch and other molecules typically used for long-term storage and structural support.

Carbon has 6 positively charged ___________ and 6 negatively charged _____________. Of these ____________, ___________ reside in the first shell and _________ reside in the second, outermost shell. To complete its outermost shell, it needs _____ more _______________ . Carbon tends to share these ____________ with _______________, the elements that comprise a majority of living organisms. It can bond with up to ____ other elements, allowing it to be the ideal building block for many and diverse _________ molecules. Carbon can form long chains, branches, or ___________ through single, double, or even triple bonds.

Carbon has 6 positively charged protons and 6 negatively charged electrons. Of these electrons, 2 reside in the first shell and 4 reside in the second, outermost shell. To complete its outermost shell, it needs 4 more electrons. Carbon tends to share these electrons with C, H, N, O, P, and S, the elements that comprise a majority of living organisms. It can bond with up to 4 other elements, allowing it to be the ideal building block for many and diverse organic molecules. Carbon can form long chains, branches, or rings through single, double, or even triple bonds.

Fat and oil production Complete the following paragraph to describe fats and oils: One __________ molecule attaches to three___________ molecules to form a ___________, more commonly known as a fat molecule. The more double bonds within a ___________ tail, the __________ the melting temperature. Oils, such as canola oil, are ____________ at room temperature because they contain primarily ______________ fatty acids. These oils are produced mostly in ___________. Fats, such as lard, are ___________ at room temperature because they contain primarily _____________ fatty acids. These fats are produced mostly in ____________.

One glycerol molecule attaches to three fatty acid molecules to form a triglyceride, more commonly known as a fat molecule. The more double bonds within a fatty acid tail, the lower the melting temperature. Oils, such as canola oil, are liquids at room temperature because they contain primarily unsaturated fatty acids. These oils are produced mostly in plants. Fats, such as lard, are solids at room temperature because they contain primarily saturated fatty acids. These fats are produced mostly in animals.

Phospholipid and steroid function Complete the following paragraph to describe the functions of phospholipids and steroids. Phospholipids have _____________ heads and _______________ tails. When they're exposed to water, they orient themselves in a ____________ layer, so that the ______________ face out towards the water or inside of the cell and the ____________ face each other. The _______________ is composed of a phospholipid bilayer that is __________ in nature. Steroids are composed of _________ fused carbon __________. Its function in the ______________ is to provide both flexibility and stability. Some steroids also function in cell to cell communication.

Phospholipids have hydrophilic heads and hydrophobic tails. When they're exposed to water, they orient themselves in a double layer, so that the heads face out towards the water or inside of the cell and the tails face each other. The plasma membrane is composed of a phospholipid bilayer that is fluid in nature. Steroids are composed of four fused carbon rings. Its function in the plasma membrane is to provide both flexibility and stability. Some steroids also function in cell to cell communication.

Polysaccharide structure and function Complete the following paragraph to describe the energy and structural uses of starch, glycogen, and cellulose: Polymers composed of monosaccharides are formed through ____________ reactions and are called ______________. Specific forms of these polymers serve several different functions. For instance, plants use ________ as a way to store glucose, either in its ____________, called amylose, or its ____________, called amylopectin. Animals use ___________ as a way to store glucose. It typically exists in a __________ and is stored in the liver. These examples of polysaccharides function well as storage molecules since they are large and _____________ in water, which prevents them from passing through the plasma membrane. But storage is not the only function suited to polysaccharides. Plants use a polysaccharide called ___________ for structural support. This molecule is comprised of ___________ molecules that are alternately flipped for increased support. Animals and fungi use ___________ for structural support. It's found in the ____________ of insects and crustaceans and makes up fungal cell walls. Bacteria use ___________ for structural support within their cell walls.

Polymers composed of monosaccharides are formed through dehydration reactions and are called polysaccharides. Specific forms of these polymers serve several different functions. For instance, plants use starch as a way to store glucose, either in its unbranched form, called amylose, or its branched form, called amylopectin. Animals use glycogen as a way to store glucose. It typically exists in a branched form and is stored in the liver. These examples of polysaccharides function well as storage molecules since they are large and insoluble in water, which prevents them from passing through the plasma membrane. But storage is not the only function suited to polysaccharides. Plants use a polysaccharide called cellulose for structural support. This molecule is comprised of glucose molecules that are alternately flipped for increased support. Animals and fungi use chitin for structural support. It's found in the exoskeletons of insects and crustaceans and makes up fungal cell walls. Bacteria use peptidoglycan for structural support within their cell walls.

Polypeptide construction Complete the following paragraph to describe how polypeptides are constructed from amino acids: Proteins are composed of ____________ that contain a(n) __________ group, an acid group, and a variable R group. These groups are arranged around a central _____________ atom. A ______________ reaction joins the ___________ together, forming a(n) ___________ bond called a ____________ bond. When two or more ___________ are bonded together, a ____________ is formed and when a chain of __________ are bonded together, a __________ is formed. The sequence of ___________ greatly influence the behavior and function of the resulting _____________.

Proteins are composed of amino acids that contain a(n) amino group, an acid group, and a variable R group. These groups are arranged around a central carbon atom. A dehydration reaction joins the amino acids together, forming a(n) covalent bond called a peptide bond. When two or more amino acids are bonded together, a peptide is formed and when a chain of amino acids are bonded together, a polypeptide is formed. The sequence of amino acids greatly influence the behavior and function of the resulting polypeptide.