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Cell and Molecular Biology Flashcards

1
Q

What are the three types of respiration?

A
  1. External: outside –> alveoli
  2. Internal: blood –> tissues
  3. Cellular: o2 + nutrients –> energy + byproducts
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2
Q

What is the composition of ATP?

A

adenine, ribose, 3 phosphates

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3
Q

What are the important parts of glycolysis?

A

Occurs where: cytosol of cells

Start/end products:

  • start = glucose
  • end = 2 net ATP (4 formed, 2 used; substrate level phosphorylation), 2 NADH, 2 pyruvate

Critical steps:

  • hexokinase: first enzyme invovled in glycolysis; phosphorylates glucose to make glucose-6-phosphate which stops glucose from leaving the cell (rxn irreversible)
  • phosphofructokinase (PFK): rate limiting step; takes phosphate off ATP to make ADP to make fructose-1,6-bisphosphate (rxn irreversible and commits glucose to glycolysis)

Require oxygen: anaerobic (no oxygen)

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4
Q

What is NADH?

A

electron carrier which has been reduced (gain e-)

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5
Q

What is NAD+?

A

electron carrier which has been oxidized (lose e-)

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6
Q

What is a kinase?

A

an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule

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7
Q

What are the important steps of pyruvate decarboxylation?

A

Occurs where: mitochondrial matrix

Start/end products:

  • start = 2 pyruvate, 2 coenzyme A
  • end = 2 acetyl-coA, 2co2, 2 NADH

Critical steps:

  • pyruvate decarboxylase complex (PDC): catalyzes the reaction between pyruvate and coenzyme A

Require oxygen: anaerobic (no oxygen)

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8
Q

How many Co2 and NADH are produced during pyruvate decarboxylation for every glucose?

A

2 Co2
2 NADH

*1 for each pyruvate

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9
Q

What are the important steps of the krebs (citric acid cycle; tricarboxylic acid cycle)?

A

Occurs where: mitochondrial matrix

Start/end products:

  • start = 2 acetyl-coA
  • end = 6 NADH, 2 FADH2, 2 GTP (ATP; substrate level phosphorylation), 4 CO2

Critical steps:

  • acetyl-coA merges with oxaloacetate to form citrate and cycle continues with 7 intermediates

Require oxygen: aerobic

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10
Q

What are the important steps in the electron transport chain (ETC)?

A

Occurs where: inner mitochondrial membrane

Start/end products:

  • start = NADH and FADH2 from glycolysis, pyruvate decarboxylation and citric acid cycle
  • 2 NADH (glycolysis); 1 NADH (pyruvate decarboxylation); 6 NADH, 2 FADH2 (krebs)
  • end = H20 and ATP (oxidative phosphorylation)

Critical steps:

  • carrier proteins I, II, III, IV embedded in inner membrane will recieve electrons from electron transporters (NADH, FADH2) and use that energy to pump protons against their concentration gradient into the inter membrane space
  • after all electrons have been passed, the final electron accepter is 1/2 o2 which will combine with the protons to make water

-proton motive force: a gradient which uses ATP synthase to catalyze the reaction of ADP to ATP and pushes a proton from the inter membrane space down the pH/electrical gradient

Require oxygen: aerobic

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11
Q

What is the final electron acceptor in the electron transport chain?

A

1/2 oxygen

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12
Q

With regards to the proton motive force, what happens when the pH of the intermembrane space is higher than normal?

A

THINK more H+ = more acidic = lower pH

This means there is less cellular respiration happening because the pH is higher and therefore less acidic which means there are less protons being pumped into the intermembrane space via the electron transport chain

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13
Q

What makes more ATP? NADH or FADH2?

A

NADH makes more ATP

  • 3 ATP per NADH because it enters at complex 1
  • 2 ATP per FADH2 because it enters at complex 2

**remember: FADH2 has a 2 so it enters at complex 2

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14
Q

What is coenzyme q (ubiquinone)?

A

Can be fully oxidized and fully reduced when passing electrons between the complexes

*carrier protein

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15
Q

What is cytochrome c?

A

Has an iron atom which catches and releases electrons between complex III and IV

*carrier protein

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16
Q

What is the total energy produced from 1 glucose molecule (prokaryotes and eukaryotes)?

A

~ 36 ATP eukaryotes and ~38 ATP prokaryotes

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17
Q

What occurs when the cell doesn’t have adequate oxygen to go through pyruvate decarboxylation, krebs cycle, or ETC?

A

fermentation

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18
Q

What are the important steps in fermentation?

A

Occurs where: cytoplasm

ALCOHOLIC FERMENTATION

Start/end products:

  • start = pyruvate
  • end = ethanol

Critical steps:

  • acetaldehyde is final electron accepter

Require oxygen: anaerobic

LACTIC ACID FERMENTATION

Start/end products:

  • start = pyruvate
  • end = lactate / lactic acid

Critical steps:

  • pyruvate becomes reduced to lactate which oxidizes NADH to NAD+

Require oxygen: anaerobic

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19
Q

What is the cori cycle?

A

A process in the liver that regenerates glucose from lactate released by muscles to be used again

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20
Q

What is a catabolic reaction?

A
  • Breaks down larger molecules into smaller molecules
  • releases energy
    *think CATabolic - you give a cat a toy and it will shred it into smaller pieces
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21
Q

What is an anabolic reaction?

A

Builds larger molecules from smaller molecules
- requires energy

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22
Q

If cells don’t have glucose, then what are the other sources of energy (and in what order)?

A
  1. Other carbohydrates
  2. Lipids
  3. Proteins
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23
Q

What is a monossacharide?

A

single, simple sugar made up of one ring

EX. glucose & fructose

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24
Q

What is a disaccharide?

A

two monosaccharides joined together

Ex. Sucrose & lactose

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25
Q

What is a polysaccharide?

A

more than two monosaccharides joined together

Ex. glycogen

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26
Q

What is glycogenesis?

A

formation of glycogen from glucose

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27
Q

What is glucogenolysis?

A

breakdown of glycogen to glucose

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28
Q

What is gluconeogensis?

A

The formation of glucose by non-carobhydrates

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29
Q

What is insulin?

A

hormone released by the pancreas when glucose is in abundance

triggers cells to:
1. make glycogen
2. under glycolysis and make ATP via the rate limiting step (PFK - phosphofuctokinase)

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30
Q

What is glucagon?

A

hormone released by the pancreas when glucose is low (*think “glucose is gone” Glu ca gon)

similar to epinehprine

triggers cells to:
1. glycogenolysis
2. inhibit glycogenesis

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31
Q

What occurs during carbohydrate digestion?

A
  1. Begins in mouth via release of salivary amylase enzymes which breakdown polysaccharide chains into smaller polysaccharides or disaccharides
  2. products will travel from stomach to duodenum where pancreatic amylase is used to break down into disaccharides
  3. then the small intestine releases disaccharidases which breakdown disaccharides into monosaccharides
  4. monosaccharides taken up by enterocyte in small intestines
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32
Q

What are lipids?

A

Long hydrocarbon chains

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33
Q

What are triglycerides?

A

glycerol + 3 fatty acid chains

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34
Q

What is lipolysis?

A

breakdown of lipids via lipase enzymes

glycerol can enter the glycolytic pathway and make ATP via glyceraldehyde 3 phosphate (DAP) (G3P) (PGAL)

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35
Q

How are fatty acid chains broken down?

A

Beta-oxidation in the matrix of the mitochondria

breaks off 2 carbons at a time at the ‘beta (second)’ carbon position

2 carbons broke off make acetyl coA

beta oxidation produces 1 NADH and 1 FADH2

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36
Q

What occurs during lipid digestion?

A

lipids are broken down starting in the duodenum

bile is released from the galbladder which emulsifies fats

pancreas releases pancreatic lipases which break down fats into glycerol and 3 fatty acid chains which become absorbed by enterocytes

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37
Q

What are the three types of lipoproteins?

A
  1. chylomicron - leave enterocytes in small intestine and enter lacteals which go to the lympatic and circulatory systems
  2. LDL - unhealthy bc low dentistry of proteins which are composed of mostly cholesterol
  3. HDL - “healthy” bc high dentisty of proteins
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38
Q

What occurs during protein digestion?

A
  1. begins in stomach where pepsin is released to breakdown proteins to smaller polypeptides
  2. in small intestine peptidase enzymes (like trypsin and chymotrypsin) and break polypeptides into smaller polypeptides until eventually they become just amino acids
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39
Q

What is the difference between an atom and a molecule?

A

An atom is made up of protons, neutrons and electrons and a molecule is two or more atoms joined together by chemical bonds

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40
Q

What are the three main types of bonds?

A
  1. ionic bonds - transfer of electrons from one atom to another where both atoms have different electronegativities
  2. covalent bonds - electrons shared between atoms of similar electronegativities
    –> polar: unequal sharing of electrons between two atoms of different electronegatitivites; results in formation of a dipole
    –> non-polar: equal sharing of electrons between two atoms of identical electronegativity
  3. hydrogen bonds - a weak bond between molecules with a hydrogen attached to a highly electronegative atom and is attracted to a negative charge on another molecule (F, O, N) – pick up the FON
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41
Q

What are the 5 most important properties of water?

A
  1. excellent solvent - The dipoles of H2O break up charged ionic molecules, making it easy for water to dissolve substances
  2. high heat capacity - The degree in which a substance changes temperature in response to gain or loss of heat. For example, the temperature of a large body of water is very stable in response to temperature changes of the surrounding air; you must add a large amount of energy to warm up this water.
  3. ice floats - Water expands as it freezes and becomes less dense than its liquid form. This is explained by the H-bonds becoming rigid and forming a crystal that keeps the molecules separated
  4. Cohesion/ Surface Tension - Water is attracted to like substances due to its H-bonds. This strong cohesion between H2O molecules produces a high surface tension that allows for phenomena like water bugs walking on water.
  5. Adhesion - water is also attracted to unlike substances. For example, you may wet your finger to easily flip pages of a book. Capillary action describes the ability of a liquid to flow without external forces.
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42
Q

What is a monomer?

A

1 unit

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43
Q

What is a polymer?

A

series of repeating monomers

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44
Q

What is the hydroxyl functional group?

A

OH

polar and hydrophilic

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45
Q

What is the carboxyl functional group?

A

COOH

polar, hydrophilic, weak acid

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46
Q

What is the amino functional group?

A

NH2

polar, hydrophilic, weak base

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47
Q

What is the phosphate functional group?

A

PO4 (3-)

polar, hydrophilic, acid

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48
Q

What is the carbonyl functional group?

A

C=O

polar, hydrophilic

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49
Q

What is the aldehyde functional group?

A

H-C=O

polar, hydrophilic

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50
Q

What is the keytone functional group?

A

R-C=O

polar, hydrophilic

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51
Q

What is the methyl functional group?

A

CH3

nonpolar, hydrophobic

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52
Q

What is a monosaccharide?

A

single sugar molecule

(i.e., glucose and fructose)

*OH down = alpha

*OH up = beta

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53
Q

What is a disaccharide?

A

two sugar molecules joined by a glycosidic linkage (occurs via dehydration reaction)

(i.e., sucrose, lactose, maltose)

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54
Q

What is a polysaccharide?

A

series of connected monosaccharides; polymer. Bonds form via dehydration synthesis and breakdown via hydrolysis.

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55
Q

What monosaccharides make up sucrose (disaccharide)?

A

glucose + fructose

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56
Q

What monosaccharides make up lactose (disaccharide)?

A

glucose + galactose

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57
Q

What monosaccharides make up maltose (disaccharide)?

A

glucose + glucose

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58
Q

A polymer of alpha-glucose molecules which store energy in plant cells.

A

starch

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59
Q

A polymer of alpha-glucose molecules which store energy in animal cells

A

glycogen

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60
Q

A polymer of beta-glucose molecules which support the structure of walls for plant cells and wood

A

Cellulose

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61
Q

A polymer similar to cellulose, except each beta-glucose group has a nitrogen containing group (n-acetylglucosamine) attached to the ring. It’s also a structural molecule in fungal cells as well as insect exoskeletons.

A

Chitin

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62
Q

What are triglycerides (triacylglycerols)?

A

structures consisting of three fatty acid chains attached to a glycerol backbone; can be saturated or unsaturated.

  • saturated: contain no double bonds and have straight chains are bad for health since the straight chains stack densely and form plaques
  • unsaturated: contain double bonds that cause kins in chains; are better for health since chains stack less densely, can be sis or trans
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63
Q

What are phospholipids?

A

comprised of two fatty acid chains and a phosphate group (+R) attached to a glycerol backbone

*are amphipathic which describes a molecule that has both hydrophobic and hydrophilic properties

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64
Q

Describes a molecule that has both hydrophobic and hydrophilic properties

A

amphipathic

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65
Q

What are steroids?

A

comprised of three 6 membered rings and one 5 membered ring include hormones and cholesterol

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66
Q

Esters of fatty acids and monohydroxylic alcohols, used as protective coating or exoskeletons (lanolin)

A

waxes

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67
Q

Fatty acid carbon chains with conjugated double bonds and six membered C-rings at each end. Includes pigments which produce colours in plants and animals (i.e., carotenes and xanthophylls)

A

Carotenoids

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68
Q

4 joined pyrrole rings that often complex with a metal

A

porphyrin

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69
Q

What are adipocytes?

A

Specialized fat cells in two categories
1. white fat cells - composed primarily of triglycerides with a small layer of cytoplasm around it
2. brown fat cells - have considerable cytoplasm, lipid droplets scattered throughout, and lots fo mitochondria

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70
Q

Similar to phospholipids but have a carbohydrate group instead of a phosphate group

A

Glycolipids

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71
Q

Lipids are insoluble so they are transported via lipoproteins, which are lipid cores surrounded by phospholipids and apolipoproteins

A

lipoprotein

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72
Q

What happens to cell membrane fluidity in cold weather?

A

cell membranes become more rigid. In order to avoid cell membrane rigidity, cholesterol and mono and poly unsaturated fatty acids are incorporated into the membrane. The incorporation of these groups increases fluidity.

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73
Q

What happens to cell membrane fluidity in warm weather?

A

Cell membranes become more fluid and flexible. In order to avoid cell membrane collapse, cholesterol is added to restrict movement. The fatty acid tails are saturated so they become straight and pack tightly, thus decreasing fluidity.

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74
Q

Polymers of amino acids joined by peptide bonds

A

proteins

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75
Q

What is the structure of an amino acid?

A
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76
Q

What are the four types of proteins?

A
  1. storage proteins - casein in milk, ovalbumin in egg whites, and zein in corn seeds
  2. transport proteins - hemoglobin carries oxygen, cytochromes carry electrons
  3. enzymes - catalyze reactions in both forward and reverse directions based on the substrate concentration. They do not change the spontaneity fo a reaction

i. enzyme efficiency is determined by temperature and pH

ii. amylase catalyzes reactions that breaks the alpha-glycosidic bonds in starch

  1. cofactors - non-protein molecules that assist enzymes; the union of a cofactor + enzyme is called an apoenzyme / apoprotein

i. if the cofactor is organic, it is a coenzyme (ex. vitamins). Cofactors can also be inorganic (ex. metal ions Fe 2+ and Mg 2+)

ii. If a cofactor is covalently bound to an enzyme, it is called a prosthetic group

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77
Q

True or False: RNA can sometimes act as an enzyme (ex. ribozyme)

A

True

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78
Q

Formed entirely of amino acids

A

simple protein

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79
Q

functional proteins that act as carriers or enzymes and are examples of simple proteins

A

albumins and globulins

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80
Q

fibrous proteins that have structural function (i.e., collagen) and are examples of simple proteins

A

scleroproteins

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81
Q

simple protein + non-protein

A

conjugated

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82
Q

protein bound to a lipid

A

lipoprotein

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83
Q

protein bound to a carbohydrate

A

Mucoprotein

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84
Q

protein bound to pigmented molecule

A

chromoprotein

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85
Q

protein complexed around metal ion

A

metalloprotein

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86
Q

contains histone or protamine bound to nucleic acid

A

nucleoprotein

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87
Q

What are the 4 levels of protein structure?

A
  1. primary - sequence of amino acids connected by peptide bonds
  2. secondary - 3D shape resulting from hydrogen bonding between amino and carboxyl groups of adjacent amino acids (alpha helix or beta sheet)
    –> hydrogen bonds, disulfide bonds, van der waals forces
  3. tertiary structure - 3D structure that forms due to non-covalent interactions between amino acid R groups (subunit interaction)
    –> non covalent interactions include H-bonds, ionic bonds, hydrophobic effect (R groups push away from water), disulfide bonds, and Van Der Waals forces
  4. 3D shape of a protein that is grouping of two or more separate peptide chains
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88
Q

Are somewhat water soluble, are mostly dominated by tertiary structure, have a diverse range of functions including: enzymatic, hormonal, inter and intracellualr storage and transport, osmotic regulation, and immune response

A

Globular proteins

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89
Q

are not water soluble, are mostly dominated by secondary structure, are made of long polymers, function to maintain and add strength to cellular and matrix structure (ex. collagen or keratin)

A

Fibrous/Structural Proteins

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90
Q

includes proteins that function as membrane pumps, channels, or receptors

A

Membrane proteins

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91
Q

What is protein denaturation?

A

Occurs when proteins are taken out of their ideal temperature, pH range, or solvent. Protein denaturation means the protein is reversed back to its primary structure and this process is usually irreversible.

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92
Q

True or False: Protein denaturation and protein digestion are the same thing

A

False

Protein denaturation reverses a protein to its primary structure, however protein digestion eliminates all protein structure, including the primary structure

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93
Q

What are nucleotides?

A

Monomers that make up nucleic acids and consist of:
- nitrogenous base
- five carbon deoxyribose sugar
- phosphate group

*don’t confuse with nucleosides, which just consist of a sugar and a nitrogenous bases

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94
Q

What is a nitrogenous base?

A

a nitrogen-containing compound that makes up a nucleotide, and can vary based on whether you have DNA or RNA

DNA

A [adenine] T [thymine] G [guanine] C [cytosine]

RNA

A [adenine] U [uracil] G [guanine] C [cytosine]

Purines “Pure As Gold” - 2 rings; adenine, guanine

Prymidines “Cut the Pye” - 1 ring; cytosine, thymine (uracil)

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95
Q

True or false: Both DNA and RNA are double stranded

A

False, RNA is single stranded

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96
Q

Describe cell theory

A
  1. all living organisms composed of cells
  2. cell is the basic unit of structure, function, and organization
  3. all cells arise from preexisting cells
  4. cells carry heriditary information
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97
Q

What is the central dogma?

A

DNA -> RNA -> Protein

98
Q

What is a stereomicroscope (light)?

A

uses visible light to view the surface of a sample

pro - can view living samples
con - has low light resolution compared to a compound microscope

99
Q

What is a compound microscope (light)?

A

uses visible light to view a thing section of a sample

pro - can view some living samples (single cell layer)
con - may require staining for good visibility

100
Q

What is a phase contrast microscope?

A

uses light phases and contrast for a detailed observation of living organisms, including internal structures

pro - has good resolution and contrast
con - not ideal for thick samples and produces a “halo effect” around perimeter of samples

101
Q

What is confocal laser scanning microscope and fluorescence?

A

used to observe thin slices while keeping a sample in tact; common method for viewing chromosomes during mitosis

pro - can observe specific parts of a cell using fluorescent tagging

con - can cause artifacts

102
Q

What is scanning electron microscope?

A

pro - view surface of 3D objects with high resolution
con - can’t use on living samples, preparation is extensive as sample needs to be dried and coated, is costly

103
Q

What is cryo scanning electron microscope?

A

similar to scanning electron microscope

pro - sample is not dehydrated so you can observe samples in their more ‘natural form’

con - can’t use on living samples, samples must be frozen which can cause artificats

104
Q

What is transmission electron microscope?

A

pro - can observe very thin cross sections in high detail and can observe internal structures with very high resolution

con - cannot be used on living samples, preparation of sample is extensive and technique is costly

105
Q

What is electron tomography?

A

not a type of microscope, but a technique used to build up a 3D model of a sample using TEM data

pro - can look at objects in 3D and see objects relative to one another

cons - same as TEM cons

106
Q

What is centrifugation?

A

used to prepare a sample for observation or further experimentation. It spins and separates liquified cell homogenates into layers based on density.

  • the most order in which cell parts separate is from most dense pelleting first, and least dense separating last

DIFFERENTIAL CENTRIFUGATION
- in cells, the order is, starting from first component to pellet at the bottom and progressively spinning faster, nuclei layer –> mitochondria –> chloroplasts/lysosomes –> microsomes/small vesicles –> ribosomes/viruses/larger macromolecules

DENSITY CENTRIFUGATION
- forms continuous layers of sediment, where insoluble proteins can be found in the pellet while soluble proteins remain in the supernatant, liquid above the pellet

107
Q

Small molecules are assembled into large molecules

A

anabolic reaction

108
Q

Large molecules are broken down into small molecules

A

catabolic reaction

109
Q

The rate of formation of reactants and products is equal and there is 0 net production

A

equilibrium

110
Q

What lowers the activation energy of a reaction, thereby accelerating the rate of the overall reaction?

A

catalyst/enzyme

111
Q

What is the role of ATP in chemical reactions and metabolic processes?

A

ATP is a common source of energy, and the compound stores its potential energy in the form of chemical energy

112
Q

What is Km?

A

Substrate concentration at 1/2 Vmax

113
Q

What are allosteric enzymes?

A

have both active and allosteric sites for binding

114
Q

What is competitive inhibition?

A

mimics the substrate and binds the active site, reaction does not complete

115
Q

How do you overcome competitive inhibition?

A

increase substrate so Km raises but Vmax does not

116
Q

What is non-competitive inhibition?

A

substance binds to an area other than the active site, reaction does not complete

117
Q

How do you overcome non-competitive inhibition?

A

increase Vmax but Km stays the same

118
Q

Describe the relationship between Km and binding affinity.

A

Low Km = high binding affinity

– only requires a small amount of substrate to become saturated

High Km = low binding affinity

– large amount of enzymes required to become saturated

119
Q

Phenomenon that occurs where an enzyme becomes more receptive to additional substrate molecules after one substrate molecule binds to an active site

A

cooperativity

120
Q

What is a channel protein?

A

provide a passageway through membrane for hydrophilic (water-soluble), polar, and charged substances

121
Q

What is a recognition protein?

A

type of glycoprotein that is used to distinguish between self and foreign (ex. major histocompatibility complex on macrophage)

122
Q

What are ion channels?

A

used to pass ions across the membrane and referred to as gated channels in nerve and muscle cells
- voltage-gated: respond to difference in membrane protein
- ligand-gated: chemical binds to open channel
- mechanically-gated: respond to pressure or vibration

123
Q

What are porins?

A

allow the passage of certain ions and small polar molecules; increase the rate of water passing in kidney and plant root cells

*less specific - if you can fit through the large passage you can go through

124
Q

What are carrier proteins?

A

specific to movement across the membrane via integral membrane protein; changes shape after binding to specific molecule that enables it to be passed across

125
Q

What are transport proteins?

A

proteins that can use ATP to transport materials across the membrane; this includes active transport (ATP driven) and facilitated diffusion (does not require ATP)

126
Q

What are adhesion proteins?

A

attach sells to neighbouring cells and provide anchos for stability via internal filaments and tubules

127
Q

What are the three major components of the cell membrane?

A
  1. phospholipid membrane permeability - allows small, uncharged, nonpolar, hydrophobic molecules to pass freely through the membrane; polar molecules may cross if they are small and uncharged
  2. cholesterol - adds rigidity to animal cell membranes under normal conditions and maintains fluidity of the membrane at lower temperatures; sterols provide analogous function in plant cells; prokaryotes do not have cholesterol in membranes but have hopanoids instead
  3. glycocalyx - a carbohydrate coat that covers the outer face of the cell wall of some bacteria and the otuer face of the plasma membrane in some animal cells; consists of glycolipids attached to the plasma membrane, and glycoproteins that may serve as recognition proteins

**functions: adhesive capabilities, barrier to infection, marks for cell-cell regonition

128
Q

How do you detatch peripheral membrane proteins?

A

peripheral membrane proteins are hydrophilic and changing salt concentration or pH to break H-bonding and electrostatic interactions

129
Q

How do you detatch integral proteins?

A

integral proteins are hydrophobic and can be destroyed using detergent

130
Q

What organelle am I?

Contains chromatin, chromosomes, histones, is the site of ribosome synthesis, and contains nucleoplasm

A

Nucleus

131
Q

General packaging structure of DNA around proteins in eukaryotes

A

Chromatin

132
Q

Tightly condensed chromatin when the cell is ready to divide

A

Chromosomes

133
Q

Serve to organize DNA which coil around it into bundles called nucleosomes; these bundles are wrapped around 8 proteins

A

Histones

134
Q

Serves as the site of ribosome synthesis

A

Nucleolus

135
Q

A dense fibrillar network inside of the nucleus of eukaryotic cells that provides mechanical support; helps regulate DNA replication, cell division and chromatin organization

A

Nuclear Lamina

136
Q

The irregular shaped region within prokaryotic cells that contains all or most of the cell’s genetic material

A

Nucleoid

137
Q

True or False: The nucleoid region is only found in prokaryotes

A

True, its analogous structure is the nucleus in eukaryotes

138
Q

What organelle am I?

The gel-like substance part of a cell where all metabolic activity occurs and contains the cytosol and organelles

A

Cytoplasm

*Think of a bowl of jello with candy embedded inside. The cytoplasm is the jello (cytosol) + candy (organelles) and the cytosol is just the jello

139
Q

What are the two subunits of ribosomes in eukaryotes? prokaryotes?

A

eukaryotes: 60S + 40S = 80S (larger S = heavier)
prokaryotes: 50S + 30S = 70S (smaller S = lighter)

140
Q

Studded with ribosomes and creates glycoproteins by attaching polysaccharides to polypeptides as they are assembled by ribosomes; is continuous with the outer nuclear membrane in eukaryotes

A

Rough Endoplasmic Reticulum

141
Q

Does not contain ribosomes and serves to synthesize lipids and steroid hormones for export. In liver cells, the smooth ER function to breakdown toxins, drugs, and toxic products via cellular reactions

A

Smooth Endoplasmic Reticulum

142
Q

Smooth and striated muscle have smooth endoplasmic reticulum’s called

A

Sarcoplasmic reticulum

143
Q

What organelle am I?

Produced from the golgi that contain digestive enzymes with low pH, and functions in apoptosis, and to breakdown nutrients, bacteria and cell debris

A

Lysosomes

144
Q

What organelle am I?

Transport of various substances in vesicles and has flattened sacs known as cisternae; cis face = incoming vesicles, trans face = secretory vesicles

A

Golgi

145
Q

What organelle am I?

Common in liver and kidney that function to breakdown substances, fatty acids, and amino acids. Can be used to modify by-products of photorespiration, and can break down fatty acids for energy; can also produce h2o2 to oxidize substrates

A

Peroxisome

146
Q

What organelle am I?

Made up of tubulin and serves to provide support and motility for cellular activities; is a spindle apparatus which guides chromosomes during division

A

Microtubules

147
Q

What is the arrangement of microtubules in flagella and cilia?

A

9+2

9 pairs of microtubules with 2 singlets in the center

148
Q

What organelle am I?

Provides support for maintaining shape, such as keratin

A

Intermediate filaments

149
Q

What organelle am I?

Made of actin and involved in cell motility; found in skeletal muscle, amoeba pseudopod and cleavage furrows

A

Microfilament

150
Q

What organelle am I?

Structures that include centrioles and basal bodies are found at the base of each flagellum and cilium and organize their development. Found in a 9x3 array. Cannot be found in plants because they lack centrioles.

A

Microtubule Organizing Centers (MTOCs)

151
Q

What organelle am I?

Moves materials between organelles or between organelles and the plasma membrane

A

Transport vacuoles

152
Q

What organelle am I?

Temporary receptacles of nutrients that merge with the cytoplasm in order to break down food.

A

Central vacuoles

153
Q

What organelle am I?

Location where plants store starch, pigments, and toxic substances such as nicotine

A

Storage vacuoles

154
Q

What organelle am I?

Found in single-celled protista organisms like amoeba and paramecium; function to collect and pump excess water out of the cell via active transport to prevent bursting

A

Contractile vacuoles

155
Q

What organelle am I?

Functions to provide support in plants, fungi, protists, and bacteria

A

Cell Wall

156
Q

What makes up plant cell walls?

A

Cellulose

157
Q

What makes up fungi cell walls?

A

Chitin

158
Q

What makes up bacteria cell walls?

A

Peptidoglycan

159
Q

What makes up archaea cell walls?

A

polysaccharides

160
Q

What organelle am I?

Found in animals in area between adjacent cells (beyond plasma membrane and glycocalyx); is occupied by fibrous structural proteins, adhesion proteins, and polysaccharides secreted by cells; functions to provide mechanical support, transmits mechanical signals between inside and outside of cells

A

Extracellular matrix

161
Q

What are focal adhesions?

A

connection of the ECM to actin filaments in the cell

162
Q

What are hemidesmosomes?

A

connection of ECM to intermediate filaments like keratin

163
Q

What organelle am I?

Found in plant cells and include chloroplasts, the site of photosynthesis; leucoplasts, which specialize to store starch, lipids, proteins, as amyloplasts, elaioplasts, and proteinoplasts, respectively, and chromoplasts which store carotenoids

A

Plastids

164
Q

What organelle am I?

Double-layered organelles that make ATP, and serve as the site of fatty acid catabolism, or beta-oxidation; have their own circular DNA and ribisomes

A

Mitochondria

165
Q

What organelle am I?

Includes microtubules, microfilaments, intermediate filaments; found in eukaryotic cells, aids in cell division, cell crawling, and the movement of cytoplasm and organelles

A

Cytoskeleton

166
Q

What organelle am I?

A network of organelles and structures, either directly or indirectly connected, that function in the transport of proteins and other macromolecules into or out of the cell; plasma membrane, endoplasmic reticulum, Golgi apparatus, nuclear envelope, lysosomes, vacuoles, vesicles, and endosomes. NOT the mitochondria

A

Endomembrane System

167
Q

Cell movement occurs via ____, which undulate like snakes, and ____, which beat in a rapid back and fourth motion

A

Flagella
Cilia

168
Q

Describe water balance within the cell (i.e., tonicity)

A

Hypotonic - higher concentration of solute inside the cell so water flows in, cell swells and bursts (cytolysis)

Isotonic - concentration of solute inside and outside of the cell is equal, so net movement of water is equal

Hypertonic - higher concentration of solute outside the cell so water flows out, cell shrinks (plasmolysis)

*water follows salt

169
Q

What are the three types of intracellular circulation?

A
  1. Brownian movement - random particle movement due to kinetic energy
  2. Cyclosis/streaming - circular motion of cytoplasm around cell transport molecules
  3. Endoplasmic reticulum - provides direct channel from plasma membrane to nuclear membrane
170
Q

What are the two types of extracellular circulation?

A

Diffusion - if cells are in close contact with external environment they can use diffusion for food and respiration. Also can be used for transportation of materials between cells and interstitial fluid

Circulatory System - if cells are far from external environment the circulatory system is used

171
Q

What are anchoring junctions (desmosomes)?

A
  • keratin filaments attached to adhesion plaques
  • bind adjacent cells via connecting adhesion proteins
  • provides mechanical stability by holding structures together
  • examples: skin epithelium, cervix/uterus
172
Q

What are tight junctions?

A
  • completely encircles cell
  • produces a seal that prevents passage of materials between cells, thus materials which do enter the cells must pass by diffusion or active transport
  • examples: cells lining the digestive tract
173
Q

What are gap junctions?

A
  • narrow tunnels between animal cells (connexins) that prevent cytoplasm of each cell from mixing
  • allow passage of ions and small molecules, essentially channel proteins of two adjacent cells
  • examples: heart for passing electrical impulses
174
Q

What are plasmodesmata?

A
  • narrow tunnels between plant cells
  • narrow tube of endoplasmic reticulum (desmotubule) will exchange material through cytoplasm surrounding the desmotubule
175
Q

What is bulk flow?

A

collective movement of substances such as blood in the same direction in response to a force or pressure

176
Q

What is passive transport?

A

The movement of materials across the cell membrane without using cellular energy

177
Q

What is simple diffusion?

A

when molecules spread from an area of high to an area of low concentration

178
Q

What is facilitated diffusion?

A

Movement of specific molecules across cell membranes through protein channels

179
Q

What is active transport?

A

movement of molecules into or out of a cell against a concentration gradient

180
Q

What is secondary active transport?

A

the use of the electrochemical gradient of one molecule to move a second molecule

181
Q

Antiport

A

two substances move in opposite directions

182
Q

Symport (cotransport)

A

two substances move in the same direcrtion

183
Q

What is group translocation?

A

process that uses energy to chemically alter the substrate during its transport to prevent it from diffusing back out

184
Q

What are the three types of endocytosis (active transport)?

A
  1. Phagocytosis - undissolved (solid) material enters cell and white blood cell engulfs the material as the plasma membrane wraps around the substance
  2. Pinocytosis - plasma membrane wraps around dissolved material (liquid)
  3. Receptor-Mediated Endocytosis - a form of pinocytosis in which specific molecules called ligands bind to receptors
185
Q

Similar to endocytosis, but encompasses transportation out of a cell

A

exocytosis

186
Q

What is the equation for Gibbs Free Energy? What can this equation tell us?

A

ΔG = ΔH - TΔS

G = Gibbs Free Energy

H = Enthalpy

T= Temperature

S = Entropy

This equation can tell us whether a reaction will proceed spontaneously or non-spontaneously

If ΔG is negative, the reaction can occur spontaneously, if ΔG is positive, the reaction is non-spontaneous.

187
Q

What happens to free energy for an exergonic reaction?

A

Spontaneous

ΔG is negative

free energy is released

188
Q

What happens to free energy for an endergonic reaction?

A

Non-spontaneous

ΔG is positive

free energy is required

189
Q

True or false: Basal Metabolic Rate (BMR) increases as body size increases

A

True

190
Q

True or false: An elephant has a higher BMR than a squirrel, but a squirrel would have a higher BMR per kg

A

True

BMR actually decreases per kg as size goes up

191
Q

What is the relationship between temperature and metabolism?

A

Increased temperature = increased metabolism

192
Q

What is the relationship between age and metabolism?

A

Increased age = decreased metabolism

193
Q

True or False: Cellular respiration is an oxidative endergonic process.

A

False, it is an oxidative exergonic process

194
Q

What is the overall reaction for cellular respiration?

A

C6H12O6 +6CO2 + 6H2O + ATP

195
Q

Why is there a difference of ATP totals for cellular respiration in eukaryotes and prokaryotes?

A

Eukaryotes ~ 36 ATP
Prokaryotes ~ 38 ATP

Prokaryotes don’t have mitochondria so they do not have to transfer two NADH molecules to the mitochondrial matrix, done via active transport, which costs 1 ATP each

196
Q

What is chemiosmosis?

A

the use of energy in a H+ gradient to drive cellular work

197
Q

True or False: ATP is a DNA nucleotide

A

False, it is an RNA nucleotide because it contains a ribose sugar

198
Q

True or False: ATP is an unstable molecule, but becomes more stable when one phosphate group is removed via hydrolysis

A

True

199
Q

The change from a less stable molecule to a more stable molecule always (releases/requires) energy.

A

Releases

200
Q

Use oxygen when it’s present (more efficient) but switch to fermentation/anareobic respiration if it isn’t

A

Facultative Anaerobe

201
Q

cannot live in the presence of oxygen

A

obligate anaerobe

202
Q

Obligate aerobe

A

cannot live without the presence of oxygen

203
Q

Do not use oxygen because they have a fermentative metabolism, but are not harmed by oxygen

A

Aerotolerant Anaerobe

204
Q

Microaerophiles

A

require oxygen concentration lower than air

205
Q

True or False: Fats store more energy than carbohydrates per carbon atom

A

True

206
Q

What is the overall reaction of photosynthesis?

A

6CO2 + 6H2O –> C6H12O6 + 6O2

207
Q

Describe the process of photosynthesis

A
  1. Pigments (chlorophyll a, chlorophyll b, carotenoids [red, orange, yellow]) absorb energy from the sun and causes electrons to become excited and unstable
  2. Electrons re-emit absorbed energy which becomes reabsorbed by nearby pigment molecules (P680 - photosystem 2, P700 - photosystem 1)
  3. Antenna pigments (chlorophyll b, carotenoids, phycobilins [red algae], xanthophylls) capture wavelengths that chlorophyll a does not, and pass energy to chlorophyll a where the direct light reactions occur
208
Q

What kind of ring does chlorophyll have

A

Porphyrin with a Mg atom inside

209
Q

Label the chloroplast

A
210
Q

The location where H+ accumulates as a result of the ETC in a chloroplast.

A

thylakoid lumen

211
Q

Suspended within the stroma and their membranes contain the two photosystems, cytochromes and electron carriers

A

Thylakoids

212
Q

Fluid material; that fills area inside the inner membrane and is the location of the Calvin cycle

A

Stroma

213
Q

Where does non-cyclic photophosphorylation take place?

A

Thylakoid membrane

214
Q

Where does cyclic phosphorylation take place?

A

Stroma lamellae - pieces connecting the thylakoids

215
Q

Where does photolysis take place?

A

thylakoid lumen

216
Q

Where does chemiosmosis take place in the chloroplast?

A

thylakoid membrane

217
Q

What happens during non-cyclic and cyclic photophosphorylation?

A
  1. Electrons trapped by P680 in PSII are energized by light
  2. Two excited e- are passed to a primary e- acceptor
  3. Excited e- enter the ETC (PSII, cytochrome proteins, FE2+ cofactor)
  4. Two e- lose energy as they move down the chain
  5. ETC ends with PSI/P700 where e- become re-energized by sunlight and passed to another primary e- acceptor

NON-CYCLIC PATH

  1. 2 e- pass down a short ETC (ferrodoxin protein), NADP+ + H+ + 2 e- form NADPH

CYCLIC PATH

  1. 2 e- from PSI join with protein carriers (cytochrome) from the first ETC and generate 1 ATP as they pass through the chain
  2. 2 e- are recycled into PSI and continue to have an option to enter the cyclic or non-cyclic path
218
Q

What occurs during the Calvin cycle?

A

Carbon fixation (gas –> solid)

  1. Carboxylation - 6 CO2 + 6 RuBP form 12 PGA and are catalyzed by RuBisCo (RuBP carboylase)
  2. Reduction - 12 ATP + 12 NADPH convert 12 PGA –> 12 PGAL (G3P) and byproducts NADP+ and ADP go into non-cyclic photophosphorylation
  3. Regeneration - 6 ATP convert 10 PGAL (G3P) –> 6 RuBP, which allows calvin cycle to repeat
  4. Carbohydrate Synthesis - Two remaining PGAL are used to make glucose
219
Q

What happens during chemiosmosis?

A

potential energy in water is used to make ATP

  1. H+ ions released into lumen when water is split by PSII and H+ also released into lumen from stroma by cytochome beween PSII and PSI
  2. pH and electrical gradient is created at pH 5 and ATP synthase generates ATP (3 H+ = 1 ATP)
220
Q

True or False: Calvin cycle (dark rxns) occurs primarily at night.

A

False, calvin cycle occurs the same time as the light rxns. It is referred to as the dark rxns because the reaction is light independent

221
Q

True or False: Calvin cycle is light-independent but it requires ATP and NADPH produced from light-dependent reactions

A

True

222
Q

What occurs during photorespiration?

A

Rubisco binds to O2 (oxygen fixation) instead of CO2
and produces NO ATP or glucose

*alternate to C3 photosynthesis

223
Q

What is the purpose of C4 photosynthesis?

A
  1. More efficient - little competition when deciding if rubisco should fix CO2 or O2
  2. Minimize photorespiration and water loss (ex. found in hot, dry climates)
224
Q

What occurs during C4 photosynthesis?

A
  1. CO2 enters leaf and moved from mesophyll to bundle sheath cells
  2. CO2 combines with phosphoenol pyruvate (PEP) to form oxaloacetate (OAA)
  3. OAA converted to malate and transferred from plasmodesmata to bundle sheath which requires conversion of 1 ATP to 1 AMP
  4. Malate converted to pyruvate and CO2. CO2 used in calvin cycle and pyruvate converted back to PEP
225
Q

What occurs during CAM (crussulacean acid metabolism) photosynthesis? What is the benefit?

A
  1. PEP carboxylase fixes CO2 + PEP to OAA forming malic acid
  2. PEP carboyxlase active during night when stomata are open causing malic acid to accumulate in vacuole
  3. During day stomata are closed and malic acid is converted back to OAA which requires 1 ATP and releases CO2 which is used in the calvin cycle

BENEFIT - Can proceed during the day when stomata are closed, reducing water loss (ex. cacti and crassulacean plants)

226
Q

Division of a cell nucleus during mitosis

A

karyokinesis

227
Q

The division of the cytoplasm during cell division

A

cytokinesis

228
Q

Label the parts of a chromosome

A
229
Q

Humans have ____ chromosomes, or ____ homologous pairs.

A

46
23

230
Q

Humans have a total of ____ chromatids

A

92

231
Q

Mitosis describes cell division in ____ cells. Meiosis describes cell division in ____ cells.

A

Somatic (body)
Sex/Germ/Reproductive

232
Q

What are the 5 steps of mitosis?

A
  1. Prophase - nuclease disassembles, nucleolus dissapears, chromatin condenses into chromosome, nuclear envelop breaks down, mitotic spindle forms, microtubules connect to kinetochores
  2. Metaphase - chromosomes line up in the middle of the cell (metapheseal plate)
  3. Anaphase - shortest step of mitosis where sister chromatids (chromosomes) are pulled by microtubules to opposite poles
  4. Telophase - nuclear division occurs, nuclear envelope develops, chromosomes become chromatin and nucleoli reappear
  5. Cytokinesis
    - ANIMAL CELLS: cleave furrow forms and plasma membrane is pulled towards centre of cells, splitting the cytoplasm
    - PLANT CELLS: cell plate forms and merges with the plasma membrane, splitting the cytoplasm

*result is two diploid cells

233
Q

When is a karyotype taken?

A

metaphase

234
Q

What are the three phases of interphase?

A

G1 - cell increases in size and proteins and ribosomes are synthesized; most variable in length and the length of the cell cycle depends on this stage

S - DNA synthesis occurs

G2 - rapid cell growth, organelles replicated

235
Q

True or false: More time is spent in mitosis than interphase (G1, S, G2), which comprises about 90% of the cycle.

A

False, interphase comprises 90% of the cycle

236
Q

What happens at the first check point in the cell cycle?

A

At end of G1, determines if growth occurred and there are favourable conditions, if no cell enters G0

237
Q

What happens at the second check point in the cell cycle?

A

At end of G2, checks for sufficient Mitosis Promoting Factor (MPF) levels

238
Q

What happens at the third check point in the cell cycle?

A

M checkpoint which occurs during metaphase and checks if all chromosomes attached to kinetochores

239
Q

What are the 4 cell cycle regulators?

A
  1. Cyclin-dependent kinases (CDK) - regulate the cell cycle via phosphorylation
  2. Growth factors - stimulate cell division (i.e., damaged cell)
  3. Density-dependent inhibition - cells stop dividing when surrounding cells density reaches maximum
  4. anchorage dependence - most cells only divide when they are attached to an external surface such as neighbouring cells or placed on a culture dish
240
Q

What are the steps of meiosis?

A

MEOISIS I

Prophase I - nuclease disassembles, nucleolus dissapears, chromatin condenses into chromosome, nuclear envelop breaks down, mitotic spindle forms, microtubules connect to kinetochores, and crossing over (synaptonemal complex forms –> ynapsis [homologous chromosome pairing], crossing over at chiasmata)

Metaphase I - homologous pairs line up along the metaphase plate

Anaphase I - homologues pulled to opposite spoles

Telophase I - nuclear membrane develops, nucleus formed and each cell is haploid

MEOSIS II

Prophase II - nuclear envelope disappears, spindle develops, NO chiasmata or crossing over

Metaphase II - chromosomes align on metaphase plate

Anaphase II - each chromosome pulled to opposite poles

Telophase II - nuclear envelope reappears and cytokinesis occurs, the result is 4 haploid cells

241
Q

How many chromosomes and exist for each part of mitosis and meiosis?

A

DAT (6 decks)

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