Unit 1 - Biochemistry Flashcards

Question

polar covalent bond

Answer 1

* type of intramolecular bond * covalent bond with an electronegativity difference (EN) of 0-1.7 * e.g. water (H₂O); ΔEN = 1.24

Answer 2

* substances that release H⁺ ions in solution (**proton donors**) * e.g. HCL

Answer 3

* substances that accept H⁺ ions (**proton acceptors**), and sometimes produce OH^- (hydroxide donors) in solution * e.g. NaOH

Answer 4

* the unit of measurement that describes the acidity or basicity of a solution * as [H⁺] concentration increases, acidity increases, and **pH decreases**

Answer 5

* chemical systems that resist significant changes in pH; releasing H⁺ in solutions too basic, and absorbing H⁺ in solutions too acidic * usually consist of specific conjugate acid-base pairs (HCO₃^-_(aq)) * proteins may also act as buffers (e.g. hemoglobin) * e.g. **carbonic acid/bicarbonate buffer system** found in kidneys to resist significant changes of pH in bloodstream: H₂O_(ℓ) + CO_2(aq) ⇄ **H₂CO_3(aq) ⇄ HCO^-_3(aq) + H⁺_(aq)**

Answer 6

the strength of an acid or base is relative to their **ionization** (breakdown) Examples: * HCl → H⁺ + Cl^-; ∴ strong acid (*complete ionization*) * CH₃ → H⁺ + CH₃COO^-; ∴ weak acid (*partial ionization*)

Answer 7

* when an acid and a base react, a **neutralization** reaction occurs: the acid and base lose their acidic and basic properties respectively, producing water and a salt * e.g. HCL_(aq) + KOH_(aq) → H₂O_(ℓ) + KOH_(aq)

Answer 8

* a.k.a. REDOX reactions * the process in which electrons are transferred from one substance to another; the molecule which accepts electrons is "oxidized" (oxidation = loss of electrons), and the molecule which gives away electrons is "reduced" (reduction = gain of electrons)

Answer 9

* groups of elements that contribute to the formation of products in biochemical reactions * allow the interaction between biomolecules

Answer 10

⎯ CO ⎯

Answer 11

the formation of a covalent bond between two molecules with the production of a water molecule

Answer 12

the breakdown of a covalent bond, due to the addition of a water molecule

Answer 13

* macromolecules composed of carbon, hydrogen, and oxygen atoms * simplest and quickest sources of energy * either simple (mono/disaccharides), or complex (polysaccharides)

Answer 14

* simple carbohydrates * ratio of C:H:O = 1:2:1 * e.g. glucose

Answer 15

classified according to the number of carbons or the functional group number of carbons: * triose sugars; have 3 carbons * pentose sugars; have 5 carbons * hexose sugars; have 6 carbons functional group: * aldoses; have an aldehyde (⎯ COH) * ketoses; have a ketone (⎯ CO⎯)

Answer 16

* simple carbohydrates composed of two monosaccharadies, combined via **α 1-4 glycosidic linkages** (dehydration synthesis) * formula for disaccharides = C₁₂H₂₂O₁₁ MUST-KNOW EXAMPLES: α-glucose + α-glucose = **maltose** α-glucose + fructose = **sucrose** α-glucose + galactose = **lactose**

Answer 17

* complex carbohydrates (carbohydrate polymers) composed of many monosaccharides via **α 1-4 glycosidic linkages**, and sometimes **α 1-6 glycosidic linkages** * number of particles - 1 = number of linkages MUST-KNOW EXAMPLES: many α-glucoses = **starch (amylopectin)** many β-glucoses = **cellulose**

Answer 18

* **glycogen** is used for temporary storage in the liver * **cellulose** gives structure and form to plants * **chitin** is found in the exoskeleton of insects

Answer 19

* macromolecules composed of carbon, hydrogen, and oxygen atoms, with a high proportion of non-polar carbon–hydrogen bonds * store energy and regulate hormones 4 main types: 1. triglycerols/triglycerides 2. phospholipids 3. steroids 4. waxes (only one not made up of fatty acids)

Answer 20

* made of a carboxylic acid as the head, and a hydrocarbon tail * max amount of H's = **saturated**; solid at room temperature (e.g. butter) * not the max amount of H's = **unsaturated**; carbon-carbon double bonds, and "kink" (bend) in the tail; liquids at room temperature (e.g. olive oil)

Answer 21

lipids composed of a glycerol molecule (C₃H₈O₃) and three fatty acids linked by **ester bonds** via **esterification** (dehydration synthesis)

Answer 22

* lipids composed of a glycerol molecule (C₃H₈O₃), two fatty acids, and a phosphate group with a *R* group; linked by **ester bonds** via **esterification** (dehydration synthesis) * made of a hydrophilic head (phosphate and glycerol), and hydrophobic tails (fatty acids); are polar molecules

Answer 23

* made up of hydrophilic heads directed towards aqueous solutions, and hydrophobic tails tucked away from aqueous solutions, interacting with each other * found in micelles and the cell membrane

Answer 24

* lipids composed of four attached carbon-based rings * are chemical messengers * aid in cell-to-cell communication * a lot of them are hormones EXAMPLES: * cholesterol (pre-cursor steroid) * estradiol (an estrogen) * testosterone (an androgen; mostly in males) * progesterone (a progestin; mostly in females)

Answer 25

* macromolecules composed of amino acid monomers linked by covalent bonds * are folded and functional **polypeptides** (peptide bonds link amino acids together) * serve many functions: including acting as enzymes, providing structural support, regulating passage of substances across the cell membrane, and maintaining pH levels

Answer 26

the process in which proteins can potentially unfold

Answer 27

* an organic molecule composed of an amino group (**amino**), a central carbon atom, an R group, and a carboxyl group (**acid**) * humans have 20 amino acids (proteins are made of up to 20 _different types_ of amino acids * can be ionized (H₃N⁺ amino group), or crystalline (H₂N amino group)

Answer 28

**1. primary structure** * linear sequence of amino acids **2. secondary structure** * hydrogen bonding between amino acids result in a coil-like shape (α-helix) or a fan-like shape (β-pleated sheet) **3. tertiary structure** * composed of one folded polypeptide * e.g. myoglobin **4. quaternary structure** * composed of many polypetides * found in bigger proteins * e.g. hemoglobin (composed of 4 subunits (polypeptides))

Answer 29

**nonpolar** * composed of H or CH₃, and *aliphatic* (open-chained) R-groups * hydrophobic **polar** * composed of O, NH₂, or SH * hydrophilic **electrically charged** * acidic (negative charge) or basic (positive charge) composed of a negative or positive change in the R-group respectively

Answer 30

amino acids are joined together via peptide bonds and dehydration synthesis; DNA specifies the order in which the amino acids follow one another

Answer 31

* either globular (e.g. hemoglobin) or fibrous (e.g. keratin) * polypeptide forming occurs in the Golgi bodies _things that affect the shape of a polypeptide:_ * **hydrogen bonds:** between two polar amino acids (can be broken with high temperature) * **proline kink:** formation of a bend in a proline amino acid, as it folds in on itself * **hydrophobic and van der Waals interactions:** hydrophobic association between two non-polar amino acids (can be broken with high temperature) * **disulfide bridge:** covalent linkage between two cysteine amino acids (very strong; needs a REDOX agent to break it) * **ionic bonds:** associations between two oppositely charged amino acids (can be broken with high temperature)

Answer 32

* macromolecules composed of nucleotide monomers * DNA or RNA * are acidic; H⁺ donors * carry genetic information

Answer 33

organic molecules composed of a phosphate group, a pentase sugar, and a nitrogenous base

Answer 34

* contains deoxyribonucleotide monomers; A, G, T, C * contains deoxyribose * serves as a guide to make proteins * homes the genetic code of an organism

Answer 35

* contains ribonucleotide monomers; A, G, U, C * contains the sugar ribose * many functions and forms (mRNA, tRNA, mtRNA, rRNA, gRNA, etc.)

Answer 36

an indicator used to identify the presence of monosaccharides and some disaccharides; turns a different colour depending on the sugar concentration * **blue colour:** nil * **light green colour:** 0.5%-1.0% concentration * **green to yellow colour:** 1.0%-1.5% concentration * **orange colour:** 1.5%-2.0% concentration * **red to red brown colour:** 2.0%< concentration

Answer 37

an indicator used to identify the presence of complex carbohydrates; turns from a brown to a blue-black colour in the presence of starch (complex carbohydrates)

Answer 38

an indicator used to identify the presence of lipids; turns from a pink to a red colour in the presence of lipids

Answer 39

an indicator used to identify the presence of proteins; turns a different colour depending on the relative amounts of peptide bonds (from "-" (none) to "+++") * **blue:** - * **pink:** + * **violet:** ++ * **purple:** +++

Answer 40

* the accepted model of the cell membrane * "Fluid": parts move around (dynamic nature; not static) * "Mosaic"; made up of many different components _features of the model:_ * **carbohydrate chains:** make up glycoproteins, which can recognize harmful cells * **protein chains:** can act as receptors * **phospholipid bilayer:** separates the **extracellular fluid** (E.C.F) and the **intracellular fluid** (I.C.F.) * **cholesterol:** stabilizes the cell membrane * **globular proteins:** can act as transport channels

Answer 41

* non-specific vehicles which can carry hydrophobic substances - even nucleic acid - for gene therapy and vaccination administration * made of phospholipids

Answer 42

* phospolipids are not static; they move laterally, or - rarely - flip flop _The degree of fatty acid tail hydrogen saturation will dictate cell membrane permeability:_ * unsatured hydrocarbon tails with kinks are more porous, and therefore **more permeable** * saturated hydrocarbon tails with no kinks are **less permeable** _The amount of cholesterol within the phospholipids will also dictate cell membrane permeability:_ * more cholesterol means **more permeability** * less cholesterol means **less permeability**

Answer 43

* **transport channel:** can transport substances into the cell * **enzyme:** acts as a biological catalyst to speed up reactions * **receptor site:** ligands bind to receptors (e.g. hormones) and change shape; the causes a cascade of reactions called "signal transduction" * **cell identity marker:** carbohydrate chains that protude from glycoproteins enable cells to recognize each other, and therefore identify "intruders"; can be used to detect various cancers and infections * **cell adhesion:** used for tissue formation * **attachment of cytoskeleton:** maintain cell shape and form (proteins, microfilaments, microtubules and spindle fibers, etc.)

Answer 44

the process of which DNA is USED (not TRANSFORMED) to create proteins **1. DNA replication:** DNA is replicated during the S phase of the cell cycle within the nucleus **2. DNA transcription:** a strand of DNA is copied into a molecule of messenger RNA (mRNA) within the nucleus **3. DNA translation:** mRNA is used in the process of protein synthesis within the RER, and polypeptide folding (packaging and modifying of proteins) within the Golgi bodies; the new protein is then excreted outside of the cell membrane via exocytosis and vesicles

Answer 45

* organic substances that speed up biochemical reactions; is mostly proteins * are specific to substrates * e.g. amyl**ase**

Answer 46

* the reactant that an enzyme acts on * e.g. amyl**ose**

Answer 47

* follows the "induced-fit model" (a.k.a. the "hand in glove model"), NOT the "lock and key model"; the enzyme/substrate changes shape to fit the other EXAMPLE: (maltose → glucose + galactose) 1. Maltase (the enzyme) binds with maltose (the substrate) at the **active site**. 2. Hydrolysis takes place, and there is a conformation change of the enzyme. 3. The enzyme recycles (reverts to it's original shape), and the glucoses (the products) are released.

Answer 48

**pH** * enzymes tend to have an optimal pH level in which they work **temperature** * increase in temperature means the enzyme _denatures_ and theres a loss of activity * decrease in temperature means the activity is reduced, but is restored when the temperature is raised (is reversible) **concentration** **presence of co-factors and co-enzymes** * co-factors are inorganic non-proteins (e.g. ions; Zn²⁺, Mg²⁺) * co-enzymes are organic non-proteins (e.g. vitamins; Vitamin B₃, NAD⁺, NADP)

Answer 49

**1. optimal conditions:** each enzyme operate at optimal conditions * e.g. pepsin (in stomach; digests proteins) will operate best at pH3 * e.g. trypsin (in duodenum; digests proteins) will operate best at pH8 **2. specificity:** every enzyme is specific for it's substrate * e.g. amylase breaks down amylose **3. sensitivity:** refers to an enzyme's binding affinity (degree of attraction) to it's substrate

Answer 50

**1. Competitive inhibitors:** the active site of the enzyme is blocked directly by the competitive inhibitor; prohibiting the substrating from binding with the enzyme **2. Non-competitive inhibitors:** the non-competitive inhibitor binds _allosterically_ (not in the active site; causing a change in the shape of the active site, and prohibiting the substrate from binding with the enzyme **3. Allosteric activators and inhibitors** * allosteric activators bind to the active site of an enzyme and keep an enzyme active, or cause an increase in activity (ACTIVE FORM) * allosteric inhibitors bind to the active site of an enyzme and causes the enzyme to be inactive, or cause a decrease in activity (INACTIVE FORM)

Answer 51

**A --(Ase)-> B --(Base)-> C --(Case)-> D** (If there's too much/not enough product (D), it can act as an allosteric activator/inhibitor to produce less/more activity at A.)

Answer 52

**1. food industry;** e.g. lactase in dairy/cheese **2. sanitation;** e.g. enzymes in detergents (doesn't work in higher temperatures), lipases **3. ethanol production;** e.g. maltases

Answer 53

the net movement of substances from an area of higher to lower concentration

Answer 54

the movement of water from an area of higher to lower concentration, across a semipermeable membrane

Answer 55

the movement of substances from an area of higher to lower concentration, without the input of energy

Answer 56

the transport of a solute across a membrane against the concentration gradient

Answer 57

process where the cell membrane ingulfs extracellular material to bring it inside the cell

Answer 58

endocytosis of solid particles

Answer 59

endocytosis of liquid particles

Answer 60

process in which a vacuole fuses with the cell membrane, and releases its contents outside of the cell

Answer 61

* equal osmotic pressure * no net movement of water

Answer 62

* lower osmotic pressure * water enters the cell; the cell grows

Answer 63

* higher osmotic pressure * water leaves the cell; the cell shrinks

Answer 64

adding more hydrogen atoms to unsaturated fats

Unit 1 - Biochemistry Flashcards

(94 cards)