Chapter 4 Flashcards
aer-
air. e.g., aerobic respiration: a respiratory process that requires oxygen.
an-
without. e.g., anaerobic respiration: a respiratory process that does not require oxygen.
ana-
up. e.g., anabolism: cellular processes in which smaller molecules are built up into larger ones.
cata-
down. e.g., catabolism: cellular processes that break down larger molecules into smaller ones.
co-
with. e.g., coenzyme: a substance that unites with a protein to complete the structure of an active enzyme molecule.
de-
undoing. e.g., deamination: process that removes nitrogen-containing portions of amino acid molecules.
mut-
change. e.g., mutation: change in genetic information.
-strat
spread out. e.g., substrate: substance upon which an enzyme acts.
sub-
under. e.g., substrate: a substance upon which an enzyme acts.
-zym
causing to ferment. e.g., enzyme: a protein that speeds up a chemical reaction without itself being consumed.
dehydration synthesis
is a type of anabolic process. For e.g., it builds up (joins) two monosaccharides to form a larger molecule: disaccharides. As it forms, one unit releases a hydroxyl group –OH, and another unit releases a hydrogen atom –H. These two react to produce a water molecule. The monosaccharides are joined by a shared oxygen atom as it becomes a disaccharide.
Hydrolysis
is a type of catabolism process. It can decompose carbohydrates, lipids, and proteins. An, e.g., hydrolysis is the reverse of dehydration synthesis in which it breaks down the molecule. Take for, e.g., disaccharides. It uses a water molecule for each bond to break it down. It takes the disaccharides and separates them to yield two monosaccharides.
Intermediary metabolism
refers to the processes that obtain, release, and use energy.
Primary metabolites
are products of metabolism essential to survival.
Secondary metabolites
are not essential to survival but may provide an advantage or enhancement. It is best studied in plants.
Catalysis
is the accelerated chemical reaction rate. An enzyme is an organic catalyst.
active site
is a region of the enzyme molecule that temporarily combines with a specific part of the substrate, forming an enzyme-substrate complex.
State two factors that influence the rate of an enzyme-catalyzed reaction.
- depends partly on the number of enzyme and substrate molecules in the cell. The reaction is faster if the concentration of the enzyme or the concentration of the substrate increases. 2. Some enzymes can catalyze only a few reactions per second, whereas others can catalyze hundreds of thousands.
Metabolic pathways
lead to the synthesis or breakdown of particular biochemicals. Enzyme-catalyzed reactions form pathways when a reaction’s product is another’s substrate. It is a sequence of enzyme-controlled reactions.
Rate-limiting enzyme
may regulate a metabolic pathway.
Negative feedback
is a mechanism in which the product of a pathway inhibits the regulatory enzyme and may control the regulatory enzyme.
Cofactor
it is the process of an inactive enzyme activating when it combines with a nonprotein component. They are additions to some enzymes that are necessary for their function. It may be an ion of an element such as copper, iron, or zinc, or a small organic molecule called a coenzyme.
Coenzyme
is a substance that unites with a protein to complete the structure of an active enzyme molecule. Many coenzymes are composed of vitamin molecules or incorporate altered forms of vitamin molecules.
Vitamins
are essential organic molecules that human cells cannot synthesize (or may not synthesize in sufficient amounts) and, therefore, must come from the diet.
Energy
is the capacity to change something; it is the ability to do work. We recognize energy by what we can do. It cannot be created or destroyed, but it can change from one form to another. Common forms of energy are heat, light, sound, electrical energy, mechanical energy, and chemical energy.
Cellular respiration
is the process that transfers energy from molecules such as glucose and makes it available for cellular use. It occurs in three distinct, yet interconnected series of reactions: glycolysis, the citric acid cycle, and the electron transport chain (oxidative phosphorylation)
Adenosine triphosphate (ATP)
is a molecule that carries energy in a form the cell can use. It is the primary energy-carrying molecule in a cell. Cells quickly die without ATP. Each ATP molecule consists of three main parts: adenine, ribose, and three phosphates in a chain.
Adenosine diphosphate (ADP)
is an Adenosine Triphosphate (ATP) molecule that lost its terminal (end) phosphate, which becomes two phosphates.
Phosphorylation
is a process that uses energy released from cellular respiration to attach a third phosphate in order to convert ADP back to ATP.
Oxidation
is a process that releases energy from glucose which is harnessed to power cellular metabolism.
Glycolysis
the breaking of glucose. It occurs in the cytosol, and because it does not require oxygen, it is sometimes referred to as the anaerobic phase of cellular respiration. It is a series of ten enzyme-catalyzed reactions that break down the 6-carbon glucose molecule into two 3-carbon pyruvic acid molecules.
Lactic acid
in anaerobic reactions, NADH and H+ donate electrons and hydrogens to pyruvic acid, thus generating lactic acid. Excess glucose in cells may be linked and stored as lactic acid.
Deoxyribonucleic acid (DNA)
are molecules that contain and maintain information that tells a cell how to synthesize a particular protein. DNA molecule is a recipe book for protein. Its molecule is a double strand consisting of two poly-nucleotide chains.
Genetic code
is the correspondence between a sequence of DNA nucleotides and a particular amino acid.
Gene
is a DNA sequence that contains the information for making a particular polypeptide.
Genome
is the complete set of genetic instructions in a cell, including the genes as well as other sequences.
Exome
is only a small part of the human genome that encodes protein.
Gene expression
The rest of the genome controls which proteins are produced in a particular cell under particular circumstances and the amounts produced.
Nucleotides
are the building blocks of nucleic acids. It consists of a 5-carbon sugar (ribose or deoxyribose), a phosphate group, and one of several nitrogenous bases.
Purines
are adenine and guanine (A, G). They consist of two organic ring structures. Purine will always bind to a pyrimidine. (T binds to A, and G binds to C).
Pyrimidine
are thymine and cytosine (T, C). They consist of a single organic ring structure.
Complementary base pairs
are the pair-bindings of A with T and G with C.
DNA replication
is the process that creates an exact copy of a DNA molecule. It happens during interphase of the cell cycle. The double-stranded structure of the DNA molecule makes replication possible.
