Exam 2

Question 1

Monosaccharide

Answer 1

-simplest form of sugar and the most basic units (monomers) from which all carbohydrates are built

Question 2

Disaccharide

Answer 2

-any substance that is composed of 2 molecules of simple sugars (monosaccharides) linked to each other

Question 3

Glycosidic linkage

Answer 3

-the two monosaccharides are joined together by an oxide linkage formed by the loss of a water molecule
-such a linkage between two monosaccharide units through an oxygen atom is called glycosidic linkage

Question 4

Polysaccharide

Answer 4

-a carbohydrate (e.g. starch, cellulose, or glycogen) whose molecules consist of a number of sugar molecules bonded together

Question 5

Starch

Answer 5

-made up of long chains of sugar molecules that are connected together
-primary role is to help plants store energy

Question 6

Glycogen

Answer 6

-main source of fuel for our cells
-when the body doesn’t need to use the glucose for energy, it stores it in the liver and muscles
-this stored form of glucose is made up of many connected glucose molecules and is called glycogen

Question 7

Glycolysis

Answer 7

-its the 1st step in the breakdown of glucose to extract energy for cellular metabolism
-consists of an energy-requiring phase followed by an energy-releasing phase

Question 8

Citric acid cycle

Answer 8

-a series of chemical reactions used by all aerobic organism to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins into carbon dioxide

Question 9

Pyruvate oxidation

Answer 9

-a biochemical reaction that involves the oxidation of pyruvate to create acetyl CoA
-oxidation is defined as either the loss of electrons or the gaining of oxygen
-in this case pyruvate loses electrons in the process of creating acetyl CoA

Question 10

Pyruvate

Answer 10

-its the output of the anaerobic metabolism of glucose known as glycolysis
-1 molecule of glucose breaks down into 2 molecules of pyruvate, which are then use to provide further energy in one of the two ways and is connecting link of various biochemical processes such as gluconeogenesis, fermentation, cellular respiration, fatty acid synthesis, etc.

Question 11

Fermentation

Answer 11

-the breaking down of sugar molecules into simpler compounds to produce substances that can be used in making chemical energy
-chemical energy, typically in the form of ATP, is important as it drives various biological processes
-fermentation doesn’t use oxygen, which is then considered “anaerobic”

Question 12

Mitochondrial matrix

Answer 12

-matrix of a mitochondrion is the mitochondrion internal spaces enclosed by the inner membrane
-several of the steps in cellular respiration occur in the matrix due to its high concentration of enzymes

Question 13

Electron transport chain

Answer 13

-is a series of four protein complexes that couple redox reactions, creating an electrochemical gradient that leads ti the creation of ATP in a complete system names oxidative phosphorylation
-occurs in mitochondria in both cellular respiration and photosynthesis

Question 14

Nicotinamide adenine dinucleotide (NADH)

Answer 14

-specifically, NADH produced in glycolysis is utilized in reactions catalyzed by lactate dehydrogenase (LDH) (82) or transported to the mitochondria for oxidation in the electron transport chain (37) to maintain the redox states (NADH/NAD+) in cytosol and mitochondria
-NADH is a coenzyme found in all living cells

Question 15

Flavin adenine dinucleotide (FADH)

Answer 15

-high energy electron carrier used to transport electrons generated in glycolysis and krebs cycle to the electron transport chain

Question 16

Chemiosmosis

Answer 16

-process of ATP synthesis using “free energy” obtained when electrons are passed to several carriers (ETC) is known as chemiosmosis
-actual point of synthesis of ATP takes place when electrons pass the inner mitochondrial membrane
-energy is released within this process, resulting in the synthesis of ATP

Question 17

Proton motive force

Answer 17

-created by the pumping out of protons by the respiratory chain complexes is in the mitochondria of most tissues mainly used to translocate protons through the ATP synthase complex, leading to the formation of ATP from adenosine diphosphate (ADP) and phosphate

Question 18

ATP synthase

Answer 18

-adenosine triphosphate (ATP) synthases are multi-subunit protein complexes that use an electrochemical proton motive force across a membrane to make the cell’s supply of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi)

Question 19

Alveolus

Answer 19

-alveoli are tiny air sacs in the lungs that take up oxygen one breathes in and keeps the body going
-they’re microscopic and are the workhorses of the respiratory system
-we have around 480 million alveoli located at the end of the bronchial tubes
-oxygen is also exchanged for carbon dioxide at alveoli

Question 20

Cooperativity

Answer 20

-kind of allosteric regulation whereby a shape change in 1 subunit of a protein caused by substrate binding is transmitted to all other subunits, facilitating binding of additional substrate molecules to those subunits

Question 21

Affinity

Answer 21

-the strength by which 2 (or more) molecules interact or bind

Question 22

Metalloprotein

Answer 22

-proteins bound by at least one metal ion
-protein metal-binding sites are responsible for catalyzing some of the most difficult and yet important functions, including photosynthesis, respiration, water oxidation, molecular oxygen reduction, and nitrogen fixation

Question 23

Carbonic anhydrase

Answer 23

-(CAs) catalyze a reaction fundamental for life: the bidirectional conversion of carbon dioxide and water into bicarbonate (HCO3-) and protons (H+)
-these enzymes impact numerous physiological processes that occur within and across the many compartments in the body
-carbonic anhydrase plays an important role in respiration by influencing CO2 transport in the blood

Question 24

Guard cells

Answer 24

-one of the paired cells in the epidermis of a plant that control the opening and closing of a stomata of a leaf
-when swollen with water, guard cells pull apart from each other, opening the stomata to allow the escape of water vapor and the exchange of gases

Question 25

Stomata

Answer 25

-cell structures in the epidermis of tree leaves and needles that are involved in the exchange of carbon dioxide and water between plants and the atmosphere

Question 26

Calvin cycle

Answer 26

-series of chemical reactions that occurs as a part of the dark reactions of photosynthesis in which carbon is broken away from gaseous carbon dioxide and fixed as organic carbon in compounds that are ultimately used to make sugars and starch as food
-its the cycle of chemical reactions where the carbon from the carbon cycle is fixed into sugars
-occurs in the chloroplast of the plant cell

Question 27

Pigment

Answer 27

-a substance that gives something a particular color

Question 28

Photosystem I

Answer 28

-an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin
-the electrons that are transferred by photosystem I are used to produce the moderate-energy hydrogen carrier NADHP

Question 29

Photosystem II

Answer 29

-membrane protein supercomplex that executes the initial reaction of photosynthesis in higher plants, algae, and cyanobacteria
-captures the light from the sun to catalyze a transmembrane charge separation
-its responsible for water splitting, oxygen evolution, and plastoquinone reduction

Question 30

Carbon fixation

Answer 30

-the process by which plants fix atmospheric carbon to form organic compounds
-all the autotrophs, bacteria, algae and plants fix atmospheric carbon dioxide by the process of photosynthesis or chemosynthesis

Question 31

Glyceraldehyde-3-phosphate

Answer 31

-known as G3P
-product of the Calvin cycle
-a metabolite that occurs as an intermediate in several central pathways of all organisms
-some of G3P is used to regenerate RuBP

Question 32

Ribulose bisphosphate carboxylase

Answer 32

-rubisco
-the cornerstone of atmospheric CO2 fixation by the biosphere
-catalyzes the addition of CO2 onto enolized ribulose 1,5-bisphosphate (RuBP), producing 3-phosphoglycerate which is then converted to sugars

Question 33

Free energy

Answer 33

-a measure of energy that is available to do work
-its a system that changes during energy transfers such as chemical reactions, and this change is referred to as ΔG or Gibbs free energy

Question 34

Exergonic

Answer 34

-an exergonic reaction (such as cellular respiration) is a reaction that releases free energy in the process of the reaction

Question 35

Endergonic

Answer 35

-one that requires free energy to proceed
-example: photosynthesis
-photosynthetic organisms conduct this reaction by using solar photons to drive the reduction of carbon dioxide to glucose and the oxidation of water to oxygen

Question 36

Catabolism

Answer 36

-all chemical or enzymatic reactions involved in the breakdown or organic or inorganic materials such as proteins, sugars, fatty acids, etc.

Question 37

Anabolism

Answer 37

-process by which the body utilizes the energy released by catabolism to synthesize complex molecules
-these complex molecules are then utilized to form cellular structures that are formed from small and simple precursors that act as building blocks

Question 38

Activation energy

Answer 38

-the minimum energy required for a reaction to occur

Question 39

active site

Answer 39

-the region of an enzyme where substrate molecules bind and undergo a chemical reaction
-consists of amino acid residues that form temporary bonds with the substrate (binding site) and residues that catalyze a reaction of that substrate (catalytic site)

Question 40

Substrate

Answer 40

-in an enzyme-catalyzed reaction, the term substrate means the same thing as reactant
-a reactant is the material used up in the reaction

Question 41

Catalyst

Answer 41

-a substrate that can be added to a reaction to increase the reaction rate without getting consumed in the process
-typically speed up a reaction by reducing the activation energy or changing the reaction mechanism
-enzymes are proteins that act as catalysts in biochemical reactions

Question 42

Enzyme activity

Answer 42

-measured in units which indicate the rate of reaction catalyzed by that enzyme expressed as micromoles of substrate transformed (or product formed) per minute

Question 43

Competitive inhibitor

Answer 43

-any molecule that can bind to the active site of an enzyme with sufficient affinity such that it can compete with the enzyme’s natural substrate and reduce enzyme activity as a result

Question 44

Allosteric inhibitor

Answer 44

-molecule that combines with the enzyme at an allosteric site is known as an allosteric inhibitor
-allosteric site isn’t a similar location to the active site
-when combined with the inhibitor, the 3-dimensional shape of the enzyme changes