Biochemistry - Human Systems Flashcards
Macromolecules:
Large, complex, organic molecules. Macromolecules are classified as polymers because they are long chains of similar chemical subunits, called monomers.
Polymers:
Long chains of similar chemical subunits.
Monomers:
Similar chemical subunits.
What are the three main classes of macromolecules that make up living things?
Carbohydrates, lipids, and proteins.
What do the three main macromolecules store?
All of these macromolecules store chemical potential energy, with lipids containing 2.25 times more energy per unit than carbohydrates and proteins.
Carbohydrates:
Macromolecules made up of carbon, hydrogen and oxygen atoms. Carbohydrates are the primary energy source in living things.
Monosaccharides:
The simplest carbohydrates, consisting of a single sugar subunit. Examples include glucose, galactose and fructose, which are all isomers of C6H12O6.
Things that end in “ose” are ______.
sugars
Disaccharides:
Simple carbohydrates composed of two monosaccharide subunits. Examples include maltose (grain sugar), lactose (milk sugar) and sucrose (table sugar).
Glucose + glucose =
Maltose.
Monosaccharide + monosaccharide =
Disaccharide.
Glucose + galactose =
Lactose.
Glucose + fructose =
Sucrose.
Polysaccharides:
Complex carbohydrates composed of many monosaccharide subunits. Examples include starch, glycogen and cellulose.
Starch:
A polysaccharide that is used to store energy in plants. It also aids in creating glucose in humans.
Glycogen:
A polysaccharide that is used to store energy in animals.
Cellulose:
A polysaccharide that makes up the cell walls of plant cells.
Lipids:
Macromolecules made up of carbon, hydrogen and oxygen atoms. Lipids function in long-term energy storage, insulation and form critical components of hormones and cell membranes. Lipids are non-polar molecules, with the exception of phospholipids. There are many different types of lipids, such as phospholipids, steroids, waxes and triglycerides (fats and oils).
Lipids are ________ molecules, with the exception of phospholipids.
nonpolar
Triglyceride:
Fats and oils. A triglyceride is composed of a glycerol molecule and three fatty acids.
Saturated Fatty Acids:
Saturated fatty acids contain only single bonds between carbon atoms. Triglycerides with saturated fatty acids are called fats and are solid at room temperature.
Unsaturated Fatty Acids:
Unsaturated fatty acids contain one or more double bonds between carbon atoms. Triglycerides with unsaturated fatty acids are called oils and are liquid at room temperature.
Proteins:
Proteins are macromolecules made up of carbon, hydrogen, oxygen and nitrogen atoms. One or more polypeptides fold into a unique three-dimensional shape, forming a protein. This shape is important in the proper functioning of the protein. The type of protein is determined by the order and number of amino acids present. Proteins are involved in a variety of functions in the human body including cellular transport, blood clotting, immunity, enzyme catalysis and muscle action.
Polypeptide:
A polypeptide is a chain of amino acid subunits joined together by peptide bonds.
If a molecule has protein what is it likely?
A protein.
Dehydrolysis:
Polymers of organic compounds are formed by the process of dehydration synthesis, also called dehydrolysis. In this process, monomers are joined together and one water molecule is produced for each new bond that is formed.
Hydrolysis:
Polymers of organic compounds are broken down by the process of hydrolysis, also called condensation. In this process, water is used to break polymers down into monomers. Hydrolysis reactions are sped up, or catalyzed, by enzymes.
Enzyme:
A protein catalyst that speeds up chemical reactions by lowering the activation energy of the reaction.
Activation energy:
The energy required to initiate a chemical reaction.
Enzymes (are/are not) consumed by the chemical reaction and can be used again.
are not
The ___________ _____ is used to explain the action of enzymes.
induced-fit model
Explain the induced-fit model.
A reactant molecule, called the substrate, binds to the active site of an enzyme forming an enzyme-substrate complex. Each enzyme has a unique three-dimensional shape that allows it to bind to specific substrate molecules. The binding of the substrate to the active site alters the shape of the active site, improving the fit between the substrate and the active site. By orienting substrate molecules correctly and providing an optimal chemical environment, enzymes allow the reaction to proceed with lower activation energy. The enzyme then releases the products and is free to catalyze another reaction.
Anabolic vs catabolic reactions:
Anabolic = Putting together. Catabolic = Taking apart
Enzymes have an optimal ___________ _____ in which they function.
temperature range
Increasing temperature increases reaction rates because…
the molecules are moving faster.
What happens if the temperature continues to increase in reactions past the optimal temperature?
The reaction rate will start to decrease because high temperatures will cause the enzyme to denature.
What happens when an enzyme denatures?
It loses its shape and the substrate will not be able to bind to the active site.
Enzymes have an optimal __ _____ in which they function.
pH range
What happens if there’s a change of pH for enzymes?
An increase in H + (aq) or OH -(aq) can disrupt the chemical bonds that are responsible for the enzyme folding into its unique three-dimensional shape. This results in the enzyme denaturing and losing its function.
What is the optimal pH level for enzymes in our body?
7.
What is the optimal temperature for enzymes in our body?
37 degrees Celcius.
What happens in an enzyme reaction if there is a change in substrate concentration?
Increasing substrate concentration results in increased reaction rate until all of the enzyme molecules are being used, at which point the reaction rate levels off.
Competitive Inhibitors:
Molecules that bind to the active site of an enzyme, preventing substrate molecules from binding to the active site.
What is maltose made of?
Glucose + Glucose
What is lactose made of?
Glucose + Galactose
What is sucrose made of?
Glucose + Fructose
Allosteric inhibition:
In allosteric inhibition, non-competitive inhibitors bind to a regulatory site, called an allosteric site, on an enzyme. This causes the active site to change shape, preventing the substrate from binding to the active site. Often the non-competitive inhibitor is the product of the metabolic pathway, so as the product accumulates, it provides feedback inhibition, slowing the initial reaction rate.
Ingestion:
Taking in food.
Digestion:
The physical and chemical breakdown of macromolecules.
Absorption:
The transport of digested substances from the bloodstream.
Egestion:
Removal of food waste from the digestive tract.
Digestive tract:
The digestive tract consists of all of the digestive organs through which food passes. Includes the mouth, the pharynx, the esophagus, the stomach, sphincters, the small intestine and the large intestine.
Accessory organs:
Accessory organs of the digestive system support the digestion of macromolecules but do not form part of the digestive tract. Includes the salivary glands, liver, gallbladder and pancreas.
The mouth/oral cavity:
The mouth, or oral cavity, forms the beginning of the digestive tract.
Teeth:
Break food into smaller pieces.
Salivary glands:
Release saliva, which contains mucus and enzymes.
Tongue:
Moves food around the mouth, forming it into a small ball called a bolus, and aids in swallowing.
The pharynx/throat:
The pharynx, or the throat, is a passageway that carries food from the mouth to the esophagus. The pharynx is a common passageway for both the digestive and respiratory systems.
Esophagus:
The esophagus carries food from the pharynx to the stomach. Food enters the esophagus through the upper esophageal sphincter (UES).
Sphincters:
Muscles that control an opening through contraction (close) and relaxation (open).
The bolus moves through the esophagus through ___________.
peristalsis
Peristalsis:
Involves a series of contractions and relaxations of smooth muscles that move contents through the digestive tract.
Lower esophageal sphincter (LES):
Controls the passage of food into the stomach.
Stomach:
The stomach is a muscular, J-shaped organ with many folds in the interior called rugae that allow it to expand. The stomach temporarily stores food, is involved in some digestion and pushes food through the pyloric sphincter into the small intestine using peristalsis.
The small intestine is a long, narrow tube with three main sections.
- duodenum 2. jejunum 3. ileum
The small intestine is much ______ than the large intestine, but it is _______ in diameter.
longer, smaller
What is the primary site of digestion and absorption of nutrients?
The small intestine.
Substances are moved through the small intestine by ___________ ______.
peristaltic action
The inner walls of the small intestine contain finger-like projections, called _____.
villi
Villi:
Increase surface area for the absorption of nutrients.
Within each villus, there is a lymphatic vessel, called a _______, and a capillary network where nutrients are ________ into the lymphatic system and the circulatory system.
lacteal, absorbed
Villi are covered with microscopic hair-like structures, called __________.
microvilli
Microvilli:
Further increase surface area.
The large intestine is a long tube that is _______ than the small intestine, but ______ in diameter.
shorter, larger
The large intestine contains the _____ and the ______.
colon, rectum
Waste is concentrated in the _____ and stored in the ______ until it can be eliminated.
colon, rectum
Substances are moved through the large intestine by ___________ ______.
peristaltic action
The liver:
The liver is an accessory organ that aids in digestion.
The liver produces ____ which consists of ____ ________ and ____ _____.
bile, bile pigments, bile salts
Bile pigments:
Contain waste products from the breakdown of red blood cells that will be eliminated in feces.
Bile salts:
Bile salt splay a critical role in the digestion of lipids.
The gallbladder:
The gallbladder is an accessory organ that temporarily stores bile produced in the liver.
The bile in the ___________ is released into the ________ of the small intestine when it is needed for digestion of ______.
gallbladder, duodenum, lipids
Ducts from the liver and gallbladder connect to the _____ _________.
small intestine
The pancreas:
The pancreas is an accessory organ that produces and secretes a variety of digestive enzymes into the duodenum of the small intestine.
A duct from the pancreas connects to the _____ _________.
small intestine
Digestion involves…
both the physical and chemical breakdown of macromolecules.
Physical digestion:
Also called mechanical digestion, involves breaking food down into smaller pieces to increase the surface area available for chemical digestion by enzymes.
Chemical digestion:
Chemical digestion involves the hydrolysis of macromolecules using enzymes.
Physical digestion begins in the _____.
mouth
Salivary Glands:
In the mouth. Release saliva to moisten and lubricate food.
What does chewing do?
Breaks food into smaller pieces to increase surface area for enzyme action and to make it easier to swallow.
Chemical digestion of starch, a carbohydrate, begins in the _____.
mouth
Salivary amylase:
Breaks down some starch into disaccharides in the mouth.