Chapter 3
Dehydration vs hydrolysis reaction
-Dehydration synthesis or condensation reaction is the removal of 2 hydrogen atoms and 1 oxygen atom to get water. Dehydration reaction synthesizes a polymer. Most macro-molecules are made with this type of reaction -Hydrolysis breaks down a polymer with water. Hydro=water Lysis=breaking or separating (with water)
Which functional group is not present in this molecule? A) carboxyl B) sulfhydryl C) hydroxyl D) amino http://web.archive.org/web/20170707201814im_/http://www.easynotecards.com:80/uploads/507/21/_6da06025_13a2d7978ef__8000_00000075.png
B
What is a "fatty acid"? What makes it considered fat? What makes it considered an acid (look at functional group).
Fats- two types of smaller molecules: glycerol and fatty acids Glycerol- three carbon alcohol with a hydroxyl group attached to each carbon Fatty acid consists of carboxyl group attached to a long carbon skeleton In a fat, three fatty acids are joined to glycerol by a linkage creating a triacylglycerol or triglyceride The major function of fats is to store energy. Fat is a compact way for animals to carry their energy sores with them
Draw an amino acid and identify: central carbon, amino group, carboxyl group, and the "R" group
https://www.khanacademy.org/test-prep/mcat/biomolecules/amino-acids-and-proteins1/v/amino-acid-structure
What happens to phospholipids when placed in water?
They are different from other lipids because the two ends of a phospholipid exhibit different behavior towards water. When added to water, they self assemble into double layered structures called "bilayers" shielding their hydrophobic portions from water.
Which statements concerning unsaturated fats is true?
They have double bonds in the carbon chains of their fatty acids.
Which nitrogenous bases are purines and which are pyrimidines?
They include the nucleobases adenine (2) and guanine (3). In DNA, these bases form hydrogen bonds with their complementary pyrimidines, thymine and cytosine, respectively. This is called complementary base pairing. In RNA, the complement of adenine is uracil instead of thymine.
What are the four main classes of macromolecules? Describe one of them- Carbohydrates
1. Carbohydrates -Fruits, veggies, grains, bread, potatoes, rice -simple carbohydrates= monosacchaides or simple sugars (glucose) -complex carbohydrates- longer starch molecules -function=major nutrients for cells and raw material for building molecules examples: Ketone- carbonyl group within carbon skeleton
What is the difference between RNA and DNA? Name two main differences.
1. DNA is double stranded and RNA is single stranded. 2. DNA sugar is Deoxyribose and RNA sugar is Ribose. 3. DNA's Thymine (T), a nitrogenous base and RNA replaces with Uracil (U), also pairs with adenine (A)
What are the four main classes of macromolecules? Describe one of them- nucleic acids
2. Nucleic acids -Disaccharides: two monosaccharides joined by a glycogen linkage (covalent bond formed between 2 monosaccharides by a dehydration synthesis reaction. -Polysaccharides: many polymers of sugar, has storage and structural roles. The structure and function of a polysaccharide are determined by its sugar molecules and the positions of glycosidic linkages Starch-storage polysaccharide of plants, consists entirely of glucose monomers Plants store surplus starch Glycogen- storage polysaccharide in animals Humans and other vertebraes store glycogen mainly in liver and muscle cells Polysaccharide cellulose is a major component of the tough wall of plant cells Like starch and glycogen, cellulose is a polymer of glucose, but the linkages in cellulose difer The difference is based on two ring forms for glucose Chitin- found in exoskeleton of arthopods, chitin also provides structural support for cell walls of many fungi
What is a monomer and what is a polymer? Use an analogy to support your answer.
A monomer is a single subunit that serves as a building block of a polymer. Monomers are linked together to form polymers. A monomer is used to build different polymers within each group. A polymer is a long molecule consisting of many similar or identical building blocks linked by covalent bonds.
What is a phospholipid? How are phospholipids different from other lipids?
A phospholipid has only two fatty acids attached to glycerol rather than three. Their structure provides a classic example of how form fits function at the molecular level.
Why are proteins so important to life? Name some ways in which proteins are used in biological systems.
A protein's specific structure determines how it works. Proteins create antibodies against viruses, by mimicking their shape. Nearly every dynamic function of a living being depends on proteins. Some proteins speed up chemical reactions, while others play a role in defense, storage, transport, movement, structural support, cellular communication.
What is the "R" group in an amino acid? Name some chemical properties of "R" groups in amino acids.
Amino acids are organic compounds which contain both an amino group and a carboxyl group. They are distinguished by the attached functional group R. Of the twenty amino acids that make up proteins, six of them have hydrocarbon R-groups
What is an isomer? What is the difference between a structural isomer, enantiomer, and a cis-trans- isomer.
An isomer is a compound that has the same number of atoms of the same element, but different structures and properties. -Structural isomers- differ in the covalent arrangement of their atoms like glucose and fructose -Enantiomer isomer- also called chiral molecules. These are isomers that mirror images of one another. Enantiomers are left and right handed versions of the same molecule. It is usually only one isomer that is biologically active. Even though they look similar, you can't overlay them and make the same molecule. -Ci-trans isomers- have covalent bonds to the same atoms, but differ in the spatial arrangment due to the inflexibility of double bonds. Cis= functional group on the same plane. trans=functional group on the opposite side
Animals use _____ Plants use ______
Animals use glycogen plants use starch
Which chemical group is most likely to be responsible for an organic molecule behaving as a base? A) hydroxyl B) carbonyl C) carboxyl D) amino E) phosphate
Answer: D
What are the four main classes of macromolecules? Describe one of them- Lipids
Do not form true polymers Unifying feature is having little or no affinity for water Lipids are hydrophobic because they consist mostly of hydrocarbons, which form nonpolar covalent bonds (they do not form HYDROGEN BONDS) Fats, phospholipids, and steroids (4 ring structures, and hydrophobic) Fats- two types of smaller molecules: glycerol and fatty acids Glycerol- three carbon alcohol with a hydroxyl group attached to each carbon Fatty acid consists of carboxyl group attached to a long carbon skeleton In a fat, three fatty acids are joined to glycerol by a linkage creating a triacylglycerol or triglyceride The major function of fats is to store energy. Fat is a compact way for animals to carry their energy sores with them Fatty acids vary in length (number of carbons) Saturated fat- max number of hydrogen atoms possible and no double bonds; solid at room tepm animal fat Unsaturated fat- one or more double bonds; liquid at room temp Fish, plant oils (avocado, vegetable oil, olive oil) Phospholipid- two fatty acids and phosphate group are attached to the glycerol 1. Two fatty acid tails are hydrophobic 2. Phosphate group and its attachments form a hydrophilic head has a hydrophobic and phillic area Phospholipid Bilayer- when added to water, they self-assmelbe into a bilyar, with the phydrophic tails pointing toward the interior Results in the bilayer arrangement found in cell membrane Boundary between a cell and its external environment Steroids are lipids by a carbon skeleton, cholesterol, important steroid, is componenet in animal cell membranes Steroids always have a four ring structure, functional groups Cholesterol-precursor for sex hormones
Describe the properties of and distinguish between the six chemical groups important in the chemistry of life
Hydrophilic Polar: 1. Hydroxyl Group (OH) - Hydrogen atom bonded to a oxygen atom, then bonded into a carbon skeleton. Alcohols. 2. Carbonyl Group (C=O) - A carbon atom linked by a double bond to an oxygen atom. If the carbonyl group is at the end of a carbon skeleton it is a aldehyde, in the middle, it is ketone. Simple sugars usually contain a carbonyl group with several hydroxyl. 3. Carboxyl Group (COOH or ionized: COO-1) - Consists of carbon double bonded to an oxygen atom as well as a hydroxyl group. The carboxyl group acts as an acid by contributing H+ to a solution 4. Amino Group (NH^2) - Has a nitrogen bonded to two hydrogens. It acts as a base by picking up an H+ from a solution. Organic compounds w/ an amino group are called amines. 5. Phosphate Group (OPO3^-2) - Consists of a phosphate atom bonded to four oxygen atoms. It is usually ionized and attached to the carbon skeleton by one of it's hydrogen atoms. Called organic phosphates, often involved in energy transfers as in ATP. Hydrophobic Non-Polar: 6. Methyl Group (-CH3) - Consists of a carbon bonded to three hydrogens. A component of DNA, affects the expression of genes.
List at least 4 bonds/interactions that hold the tertiary structure together in proteins
Ionic bond, hydrogen bond, hydrophobic interactions, polypeptide backbone
What are the four levels of structure in a polypeptide chain? Describe each.
MEMORIZE PAGE 60-61 1) Primary structure-Order of amino acids in the polypeptide chain 2) Secondary structure-Think about a spiders web, made out of protein, made from B pleaded sheet 3) Tertiary Structure: R-Group interactions- Got a 3D shape, formed by interaction of hydrophilic ares Instead of being a weak link in the hydrogen bond, it is actually a strong bond between the cultures? What the **** 4) Quaternary Structure-3 polypeptides Hemoglobin is a good example for showing different types of structure, amino acid chain creates alpha subunits, hydrophobic areas in the internal, hydrophilic in the external
Why are nucleic acids important to life?
Nucleic acids store, transmit, and help express heredity information Nucleic acids are vital for cell functioning, and therefore for life. There are two types of nucleic acids, DNA and RNA. Together, they keep track of hereditary information in a cell so that the cell can maintain itself, grow, create offspring and perform any specialized functions it's meant to do. Nucleic acids thus control the information that makes every cell, and every organism, what it is.
Which nitrogenous bases will pair with each other between two strands of DNA?
One key point to notice in the DNA double helix structure is that the planar nitrogenous bases from the two strands are pointing toward each other, in the middle of the helix. Pairs of nitrogenous bases are set in the same plane, and interact with each other via hydrogen bonding.
define organic compounds, hydrocarbons, and carbon skeleton
Organic compounds - Are carbon based molecules, which usually contain hydrogen as well Hydrocarbons - Like the name suggests, molecules that only contain hydrogen and carbon Carbon Skeleton - Backbone of most organic molecules, formed by large chains of carbon Isomer - Compounds with the same formula but different structure
The structural level of a protein least affected by a disruption in hydrogen bonding is the
PRIMARY LEVEL
Why is the structure of a protein so important to its function?
Protein structure is important for the basic structure of cells because it is through small molecular interactions that they are enabled to do their job. Proteins can have structural functions, enzymatic functions, signaling functions, and rarely be used to store energy.
Describe the role of chaperone proteins.
The Role of Chaperones in Protein Folding. Chaperones are a group of proteins that have functional similarity and assist in protein folding. They are proteins that have the ability to prevent non-specific aggregation by binding to non-native proteins.
Define denaturation of a protein. Name environmental factors that can influence the shape of a protein
The denaturation of a protein is when the weak chemical bonds within a protein are destroyed, causing the protein to lose its shape. Most proteins become denatured if they are transferred from an aqueous envrionment to a nonpolar solvent, such as chloroform. High temperatures can lead to protein denaturation. Heat can disrupt hydrogen bonding and hydrophobic interactions.
What is the difference between a trans and a cis fatty acid?
The difference between cis and trans is that the two H atoms are on the same side of the double bond (cis), compared to being on opposite sides (trans). This may not seem like much of a difference, but it affects the shapes of the molecules. In a cis configuration, the double bond creates a kink in the fatty acid.
What makes phospholipids hydrophilic on one side?
The hydrophilic heads of the molecules are on the outside of the bilayer, in contact with the aqueous solutions inside and outside of the cell. the hydrophobic tails point toward the interior of the bilayer, away from the water. The phospholipid bilayer forms a boundary between the cell and its external environment.
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotide together. What would happen to DNA molecules treated with these enzymes?
The phosphodiester linkages of the polynucleotide backbone would be broken.
What is the C- and the N- terminus of a peptide chain?
the N terminal end of the polypeptide has a free amine group the C terminal end of the polypeptide has a free carboxyl group
