Enzyme & Digestion Review AP Bio

What affects enzyme reaction rates?

1) Temperature (increase temp. increases reaction rate, optimal temp. produces max reaction rate, above optimal temp. denatures the protein;reaction rate drops then stops. 2) pH (optimal pH, above or below optimal stops the reaction and denatures the enzyme 3) Concentration of the substrate 4) Concentration of the enzyme

What are some evolutionary adaptations in the digestive system of vertebrates?

1) dental adaptations (teeth structure correlates with diet in mechanical food processing), 2) stomach & intestinal adaptations (large stomachs in carnivores relate to going a long time before finding more prey, while digestive tracts are longer in herbivores and omnivores than carnivores because vegetations harder to digest. Thus, longer tracts give more time for digestion and more SA for absorption), 3) Mutualistic adaptations (mutually beneficial for 2 species.

Induced fit model

1) substrate binds to active site 2) interaction between substrate and active site 3) bonds are formed (enzyme slightly changes shape); substrates held close together=form bonds, substrate stressed= break bond 4) Product(s) released

What is an allosteric site?

2 or more subunits; active or inactive forms of enzymes

Quaternary protein structure

2+ subunits of tertiary bonds bonded together (globular protein)

TATA Box

A promoter DNA sequence crucial in forming the transcription initiation complex.

2 subdivisions of metabolism

Anabolic: A metabolic pathway that consumes energy to synthesize a complex molecule from simpler compounds. Catabolic:A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds

1st Law of Thermodynamics

Energy cannot be created or destroyed

Secretin

Hormone produced by cells of the duodenum to cause the pancreas to release bicarbonate ions to neutralize the acidity of the chyme in the small intestine

CCK

Hormone produced by the small intestine and cells of the duodenum to stimulate the gallbladder to release bile and the pancreas to release enzymes

extracellular

Located or occurring outside a cell or cells

Translation

RNA -> Protein, coded genetic information on mRNA is directed to code for a specific protein on a ribosome located in the cytoplasm

RNAi

RNA interference; stops gene expression at transcription by using a short interfering RNA to make double-stranded RNA.

2nd Law of Thermodynamics

Spontaneous energy transfer or transformation increases the disorder of the universe

bolus

a ball of food

alimentary canal

a complete digestive tract, consisting of a tube running between a mouth and the anus. (ex. earthworm, human)

Bile

a digestive juice secreted by the liver and stored in the gallbladder. converts large fat globules into fat droplets.

epiglottis

a flap of cartilage that covers the windpipe while swallowing

What is a substrate?

a molecule upon which the enzyme reacts

Cofactors

a nonprotein helper. an inorganic molecule (metal ions: Fe2+)

Coenzyme

a nonprotein helper. organic molecules (vitamin), and electron acceptors. essential for the activity of enzymes

sphincter

a ring of muscle that contracts to close an opening

Anticodon

a triplet of nucleotide base pairs that match with the mRNA sequence on tRNA

Codon

a triplet of nucleotides on mRNA to code for an amino acid

Tertiary protein structure

all other reactions are made: ionic bonds, vanderwaals, hydrogen bonds and disulfide bridges

Essential nutrients

amino acids (eggs, meat and cheese), fatty acids (seeds, grains, and vegetables), vitamins (B,C, D), and minerals (iron, calcium)

Building blocks of proteins

amino acids. digestion starts in the stomach

heterotroph

an organism that cannot make its own food

Noncompetitive inhibitor

attaches to a different portion of enzyme causing the active site to change shape

Which nutrients go directly to the blood stream?

carbohydrates, proteins, and nucleic acids

Gastrovascular cavity

central cavity with a single opening. pathway of food and wastes is both passed through the same opening. ew (ex. hydra)

What enzymes CANNOT do...

change in a reaction, make a reaction occur that wouldn't occur naturally

HCl (hydrochloric acid)

chemical made in the stomach that helps break down food. It is often called stomach acid.

Competitive Inhibitor

competes for the active site . becomes inactive until the inhibitor leaves

disaccharides

converts disaccharides into monosaccharides

aminopeptidase & carboxypeptidase

converts small polypeptides into amino acids

Transcription

double stranded DNA -> single stranded RNA. takes place in the nucleus of the cell

Bulk feeder

eat relatively large pieces of food

Suspension/ Filter feeders

eat small organisms or particles, or use a filtering structure to obtain food

Kinetic Energy

energy of an object's motion (ex. in digestion, to move the jaw muscle to chew food and throat muscles to swallow food)

Potential Energy

energy that is stored and held in readiness (ex. in digestion, to store extra energy as fat which could be used later if needed)

Activation Energy

energy to start a reaction

Difference between pepsin and pepsinogen?

enzyme pepsin- actively breaks down food in the stomach while pepsinogen- is an inactive form of pepsin synthesized and stored in cells lining the gastric pit of the stomach

Bicarbonate ions

enzyme that changes carbon dioxide into water so it is not poisonous to the body. found in pancreatic juices

nucleases

enzyme that converts DNA and RNA into nucleotides

lipase

enzyme that converts fat droplets into glycerol

trypsin & chymotrypsin

enzyme that converts polypeptides into smaller polypeptides

amalyse- pancreatic and salivary

enzyme that converts polysaccharides into.. pancreatic: other disaccharides salivary: smaller polypeptides

pepsin

enzyme that converts proteins into small polypeptides

Difference between trypsin and trypsinogen?

enzyme trypsin- actively breaks down proteins in the small intestine and is secreted by the pancreas while trypsinogen- is an inactive form trypsin that is formed in the duodenum

Which nutrients go directly to the lymph system?

fats/lipids

gastrin

hormone produced by the stomach to produce gastric juices

insulin

hormone that converts glucose into glycogen in the liver and is produced by the pancreas

glucogen

hormone that is released when blood sugar is low and is produced by the pancreas

What is an active site?

is a groove/pocket which binds with the substrate.

Secondary protein structure

level in which there are alpha and beta sheet formations being made; held together by hydrogen bonds

Primary protein structure

level in which there is just a chain of amino acids (polypeptide); held together by peptide bonds

chyme

liquid mixture of food and stomach fluids released from the stomach into the small intestine

Substrate feeder

live in or on their food source

RNA Processing

modification of RNA before it leaves the nucleus with additions and deletion;, a process unique to eukaryotes

Building blocks carbohydrates

monosaccharides. digestion starts in the oral cavity

Building blocks of nucleic acids

nucleotides. digestion starts into the small intestine

How does the body regulate HIGH blood sugar levels?

pancreas monitors with receptors -> insulin acts on liver -> liver converts glucose to glycogen -> glucose (sugar levels) normal

How does the body regulate LOW blood sugar levels?

pancreas monitors with receptors-> glycogen acts on liver -> liver converts glycogen to glucose -> glucose (sugar levels) normal

ingestion

process of taking in food

What enzymes CAN do...

raise reaction rate by lowering activation energy, form temporary enzyme-substrate complexes, and remain unaffected by the reaction

Endergonic Reactions

reactions that absorb energy (ex. ATP light energy is converted into chemical energy)

Exergonic Reactions

reactions that release energy (ex. ATP cellular respiration)

What is the purpose of an enzyme?

serves as a catalyst to speed up reaction by lowering activation energy

Fluid feeder

suck nutrient rich fluid from a living host to survive

excretion

the bodily process of discharging waste matter

extracellular digestion

the breakdown of food in compartments continuous with the outside of an animal's body

Intracellular digestion

the breakdown of food inside vacuoles steps: 1) phago/pinocytosis, 2) vacuoles fuse with lysosomes containning hydrolytic enzymes, 3) food contacts enzymes, 4) digestion occurs

What are considered accessory organs?

the liver and the gallbladder

digestion

the organic process by which food is converted into substances that can be absorbed into the body

absorption

the process of absorbing nutrients into the body after digestion. mostly takes place in the small intestine

peristalsis

the process of wave-like muscle contractions of the alimentary tract that moves food along

Why must an organism have essential nutrients?

to sustain a healthy diet. having too little can cause malnutrition (ex. little iron= tiredness) and having too much can also cause malnutrition (ex. too much iron= accumulates in the liver tissues and can lead to liver failure)

what causes a protein to denature?

too high of temp. or pH. at tertiary and quaternary levels

Metabolism

totality of an organism's chemical reactions

Building blocks of fats/lipids

triglycerol. digestion starts in the small intestine

intracellular

within a cell