89 terms

Biology Chapter 3

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Organic Compounds
A chemical compound containing carbon and usually synthesized by cells
Hydrocarbons
Chemical compounds composed of only carbon and hydrogen [All nonpolar molecules]
Carbon Skeleton
Chain of carbon atoms in an organic molecule [can be unbranched or branched; may include double bonds]
Isomers
Compounds with the same formula but different structures
Functional Groups
The groups of atoms in an organic molecule that usually participate in chemical reactions - 5 functional groups are... hydroxyl group, carbonyl group, carboxyl group, amine group, and phosphate group
Hydrophilic
Water-loving
Hydroxyl Group
--OH
Carbonyl Group
C==O
Carboxyl Group
COOH
Carboxylic Acids
Compounds within carboxyl groups
Amino Group
(A base) NH₂
Amines
Organic compounds with an amino group
Phosphate Group
PO₄
Macromolecules
A molecule having a molecular weight in the range of a few thousands to many millions (Carbohydrates, Lipids, Proteins, and Nucleic Acids)
Polymers
A large molecule consisting of many identical or similar molecular units strung together (Multiple chemical units)
Monomers
The building blocks of polymers (One chemical unit)
What is the key to diversity of protein and DNA molecules?
Arrangement (Variation in the sequence in which the monomers are strung together as well as the length of the polymer)
Dehydration Synthesis
A reaction that removes a molecule of water, linking monomers together (making of macromolecule) - requires help of enzyme
Hydrolysis
A chemical process that breaks down macromolecules by adding water molecules to the bond linking their monomers (Reverse of dehydration synthesis) - requires help of enzyme
Carbohydrate
(Almost all hydrophilic!!!!) A class of molecules ranging from the small sugar molecules dissolved in soft drinks to large polysaccharides, such as the starch molecules we consume in pasta
Monosaccarides
Single-unit sugars (glucose, galactose, and fructose) (Normally in formula of CH₂O)
Pentoses
Five-carbon sugars
Hexoses
Six-carbon sugars
Disaccharide
Two monosaccharides formed by a dehydration reaction (maltose and sucrose)
What is sucrose made of?
One glucose molecule and one fructose molecule
Polysaccharides
Polymers of monosaccharides linked together by dehydration synthesis (storage molecules and structural purposes)
Starch
SUGAR STORAGE Polysaccharide that stores glucose monomers in the roots and other tissues of plants
Glycogen
Polysaccharide that stores glucose in an animal (specifically in their liver)
Cellulose
STRUCTURAL PURPOSES A large polysaccharide composed of many glucose monomers linked into cable-like fibrils that provide structural support in plant cell walls (Most abundant organic compound on Earth)
Lipids
Diverse compounds that consist mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds (Hydrophobic) (Fats, waxes, and oils)
Fat
A large lipid made from glycerol and fatty acids (stores more than 2x energy than carbohydrates)
Triglyceride
A fat that consists of three fatty acids and a glycerol molecule
Saturated
Fats with the maximum number of hydrogens (all single bonds) - (Most animals)
Unsaturated
Fats with double bonds (less than the max number of hydrogens) - Cause kinks in carbon chain - (Most plants)
Phospholipids
(Important!! ...But not now) Major component of cell membranes; Consists of two fatty acids and phosphorus
Waxes
Consist of one fatty acid and linked to an alcohol; More hydrophobic than fats
Steroids
Lipids whose carbon skeleton is bent to form four fused rings (honeycomb... no carbon skeleton); all have same ring pattern - three 6-sided rings and one 5-sided ring
Cholesterol
(Lipid... steroid) Common in animal cell membranes; starting material for making other steroids
Anabolic Steroids
Synthetic variants of male hormone testosterone (builds up muscle and bone mass)
Protein
Means "first place" (IMPORTANT!!) Polymer constructed from amino acid monomers - Cell structure and organisms, what they do
Enzymes
(Most important role as a protein!!!) Chemical catalysts that speed and regulate virtually all chemical reactions in cells
Hemoglobin
Signal protein (In red blood cells) Transport protein that delivers O₂ to working muscles
Antibody
Defensive protein in the immune system
Amino Acids
All have an amino group and a carboxyl group (makes it an acid); monomer of proteins... or building blocks of proteins
What are proteins build from?
Only 20 different kinds of amino acids (arranged in different sequences)
What helps proteins dissolve in aqueous solutions inside cells?
Polar and charged amino acids
Peptide Bond
Covalent linkage between two amino acid units in a polypeptide; formed by dehydration synthesis
Polypeptide
A chain of amino acids
In what way is the production of a dipeptide similar to the production of a disaccharide?
In both cases, the monomers are joined by a dehydration reaction
What determines a protein's function?
Its specific 3D shape (Nearly all proteins must recognize and bind to some other molecule in order to function)
Denaturation
Process in which polypeptide chains unravel, losing their specific shape (and their function)
Primary Structure
Unique sequence of amino acids (has to be specific and correct for it to perform its function); determined by genetic information
Secondary Structure
Regular patterns of coils or folds
Alpha Helix
Coiling a polypeptide chain (many fibrous proteins have this over most their length)
Pleated Sheet
Folding of a polypeptide chain (core of globular proteins)
Tertiary Structure
Overall 3D shape (global or fibrous) - Generally interactions among R groups of amino acids
Quaternary Structure
NOT ALL PROTEINS HAVE THIS - Shape resulting from association of two or more subunits
A decade after being awarded a Nobel Prize in Chemistry, Pauling received the Nobel Peace Prize for _____.
His efforts leading to a ban on nuclear testing
Nucleic Acids
Polymers that can serve as the blueprints for proteins (DNA and RNA)
Deoxyribonucleic Acid
Genetic material organisms inherit from their parents; a double-stranded helical macromolecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T)
Ribonucleic Acid
Nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some virus
Genes
Specific stretches of a DNA molecule that program the amino acid sequences (primary structure) of proteins
What does DNA control?
The life of the cell and the organism
Nucleotides
Monomers that make up nucleic acids; consists of three parts: 5 carbon sugar, phosphate group, and nitrogenous base
Nitrogenous Base
Organic molecule that is a base containing the element nitrogen (A, T, C, G, U)
Polynucleotides
A nucleic acid polymer
Double Helix
(DNA) Two polynucleotides wrap around each other
How do nitrogenous bases bond?
Hydrogen bond
7 major classes of protein
structural, contractile, storage, defensive, transport, signal, and enzyme
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
Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule like citric acid to be acidic?
Carboxyl
Although the structures of the functional groups important to life vary in chemical structure, they share on thing in common: They _____.
Are all hydrophilic and increase the organic compound's water solubility
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they _____.
All share the same functional group: a hydroxyl
Carboxyl is to _____ as _____ is to base.
acid, amino
Is carboxyl an acid?
YES
Is an amine group an acid?
NO
Is a carbonyl an acid?
...
Is hydroxyl an acid?
...
Carbohydrates are mainly used in our bodies _____.
As fuel
Generally, animals cannot digest the linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?
Microorganisms in their digestive tracts hydrolyze the cellulose to glucose
Is energy source a function of carbohydrates?
YES
Is enzymatic catalysis a function of carbohydrates?
NO
Is cellulose digestible by animals?
NO
A glucose molecule is to starch as a nucleotide is to _____.
A nucleic acid
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.
Contain fewer double bonds
The ovalbumin in egg white can be classified as which type of protein?
Storage
What do nucleic acids and proteins have in common?
They are large polymers
The peptide bond is a _____ bond.
Covalent
What does "polypeptide" specifically refer to?
The linkage of amino acids by dehydration synthesis