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Biology 103 1 sem > Week 3 > Flashcards

Week 3 Flashcards

1
Q

4 classes of macromolecules:

A
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
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2
Q

Biomolecule -

A

any chemical molecule that is a structural or functional component of living organisms

Chemical elements that participate in the synthesis of biomolecules structures: C, H, O, N, S, P

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3
Q

polymer and what classes are polymers:

A
  • a long molecule consisting of many similar building blocks (monomers)
  • Carbohydrates (monosaccharides)
  • Proteins (amino acids)
  • Nucleic acids (nucleotides)
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4
Q

Dehydration reaction (condensation reaction):

A

2 monomers bond together through the loss of a water molecule

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5
Q

Enzymes -

A

macromolecules that speed up the dehydration process

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6
Q

Hydrolysis -

A

reaction that is the reverse of the dehydration reaction: disassembles polymers to monomers

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7
Q

Carbohydrates molecular formula and ex

A

(CH2O)n

ex:
- Pentoses: C5H10O5 (ribose, deoxyribose) (n=5)
- Hexoses: C6H12O6 (glucose, fructose) (n=6)

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8
Q

what are biologically important carbohydrates are also called?

A

sugars

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9
Q

4 categories of carbohydrates:

A
  1. Mοnosaccharides: (CH2O)n where n = 3-7
    ex: glucose and fructose
  2. Disaccharides: made by 2 monosaccharides
    ex: maltose, sucrose, and lactose
  3. Οligosaccharides: composed by 20-30 monosaccharides
  4. Polysaccharides: composed by many glucose subunits
    ex: starch, glycogen, cellulose
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10
Q

most common monosaccharide

A

Glucose (C6H12O6)

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11
Q

Functions of monosaccharides:

A
  • fuel for cells
  • raw material for building molecules (ex: glycoproteins, proteoglycans)
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12
Q

Monosaccharides are classified by:

A

– The location of the carbonyl group: as aldose (>C=O at the end) or ketose (>C=O in the middle)
– The number of carbons in the carbon skeleton

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13
Q

Monosaccharides: structure

A

May be linear but in aqueous solutions many sugars form rings, b/c it’s more E favourable => in the cell it’s rings

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14
Q

Disaccharides (Sugars): consist of? name of the bond? examples (3)?

A
  • Consist of 2 monosaccharides
  • Covalent bond b/w the molecules is called a glycosidic linkage

ex:
Glucose + galactose = lactose (milk)
Glucose + glucose = maltose (beer)
Glucose + fructose = sucrose (sucrose - white sugar)

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15
Q

Polysaccharides and their functions:

A
  • the polymers of sugars
  • have storage and structural roles
  • structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages
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16
Q

Storage Polysaccharides:

A
  • Starch
  • Glycogen

– Polymers consisting entirely of glucose monomers

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17
Q

Starch

A
  • the major storage polysaccharide in plants
  • α-glucose polymer
  • consists of 2 polysaccharides: amylose (20-30%) and amylopectin (70-80%)
  • plants store excess starch as granules within chloroplasts and other plastids (called amyloplasts)
  • α-linkage (-OH group at C2 is in the same plane w/ -OH-group at C1) => helical molecule => granules
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18
Q

Glycogen

A
  • storage polysaccharide in animals
  • humans and other vertebrates store glycogen mainly in liver and muscle cells as cytosolic granules
  • it is branched - easier f/ hydrolysis, better access f/ enzymes
  • α-glucose polymer
  • α-linkage (-OH group at C2 is in the same plane w/ -OH-group at C1) => helical molecule => granules
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19
Q

Structural Polysaccharides

A
  • Cellulose: in plant cell walls
  • Chitin: in fungal cell walls and arthropod
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20
Q

Cellulose:

A
  • found in plant cell wall
  • an unbranched β-glucose polymer (-OH group at C2 is in diff side of the plane than the -OH group in C1)
  • diff glycosidic linkages from starch: β-linkage = linear molecule => cell wall component
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21
Q

Humans can digest ___ but not ___

A

Humans can digest starch but not cellulose => Cellulose in human food passes through the digestive tract as insoluble fiber

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22
Q

Chitin (where found? monomer? linkage? clinical correlation?)

A
  • Found in the exoskeleton of arthropods and fungal cell walls
  • Used to make surgical thread (!)
  • monomer: β-NAG (N-acetyl-glucosamine)
  • diff glycosidic linkages from starch: β-linkage = linear molecule => cell wall component
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23
Q

Lipids

A
  • the one class of large biological molecules that do not consist of polymers (of diff types of components)
  • hydrophobic
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24
Q

Biologically important lipids:

A
  1. Fats
  2. Phospholipids
  3. Steroids
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25
Q

Fats (structure, fn)

A
  • structure: glycerol + 3 fatty acids => triglycerides
  • storage form of fat
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26
Q

Fatty acid structure:

A

R- COOH, where R= long hydrocarbon chain (usually 16-18 carbons)

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27
Q

Fatty acids vary in:

A
  • length (number of carbons)
  • number and locations of double bonds
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28
Q

Saturated fatty acids (formula, characteristics, 3 examples):

A
  • molecular formula: CH3(CH2)nCOOH
  • have max # of H atoms possible => have no double bonds => solid at room T
  • mostly found in animals

ex:
Stearic acid (18:0): 18 C, 0 double bonds
Palmitic acid (16C)
Butyric acid (4 C)

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29
Q

Unsaturated fatty acids:

A
  • unsaturated fats or oils
  • have 1 or more double bonds => bending => liquid at room T
  • mostly found in plants and fish

ex:
Oleic acid - monounsaturated fatty acid (18:1)
Linoleic acid - polyunsaturated fatty acid (18:2)

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30
Q

Stearic acid

A

18 C
saturated

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31
Q

Palmitic acid

A

16 C
saturated

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32
Q

Οleic acid

A

18 C
unsaturated

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33
Q

Saturated fats: health risks

A

diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits

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34
Q

Diff molecular effects of saturated and unsaturated fats on the liver

A
  • Unsaturated fats actually reduce LDL-bound (“bad”) cholesterol levels and maintain HDL-bound (“good”) cholesterol (signal to the liver to take up cholesterol from the blood => improve cholesterol levels)
  • Saturated fats directly increase LDL-bound (“bad”) cholesterol levels
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35
Q

Functions of fat:

A
  • energy storage (humans and other mammals - in adipose cells)
  • cushions vital organs
  • insulates the body
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36
Q

Phospholipids:

A

have only 1 or 2 FA & phosphate group instead of 3rd FA

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37
Q

2 types of phospholipids:

A
  1. Phosphoglycerides: glycerol + 2 fatty acids + phosphate + organic molecule
  2. Phosphosphingolipids: sphingosine + 1 fatty acid + phosphate + organic molecule
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38
Q

Phospholipids’ Function:

A

important components of biological membranes

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39
Q

Phospholipid structure in terms of affinity to water

A

Amphipathic molecules: consist of a hydrophilic “head” and hydrophobic “tails”

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40
Q

Common membrane phospholipids and their structures (5):

A

Phosphatidyl-choline: Glycerol + Choline
Phosphatidyl-ethanolamine: Glycerol + ethanolamine
Phosphatidyl-serine: Glycerol + Serine
Phosphatidyl-inositol: Glycerol + inositol
Sphingomyelin: Sphingosine + choline

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41
Q

Bilayer arrangement:

A

When phospholipids are added to water, they self-assemble into a bilayer, with the hydrophobic tails pointing toward the interior

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42
Q

Steroids

A
  • lipids characterized by a carbon skeleton consisting of four fused rings

exs:
Cholesterol - steroid found in animal cell membranes, precursor f/ some hormones (steroid hormones - estradiol & testosterone)
Ergosterol - in fungal membrane, target for antimicotic antibiotics

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43
Q

Cholesterol: health risks

A
  • Cholesterol circulates in blood bound to lipoproteins:
    HDL - high density lipoproteins: protein > cholesterol => travels fast into bloodstream and targeted-deposited directly into the liver
    LDL - low density lipoproteins: cholesterol > protein => travels slower into bloodstream and leaves bits and pieces around => atheromatic plaque formation (cholesterol+ platelets)
  • Lipoproteins are recognized by their receptor on the PM of liver cells (hepatocytes)
  • cells take in the lipoproteins-cholesterol vesicles => receptor-mediated endocytosis
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44
Q

Proteins’ function (6):

A
  1. structural support by structural proteins (ex: collagen, elastin, keratin)
  2. storage by storage proteins (ex: ovalbumin, casein)
  3. transport by transport proteins (ex: hemoglobin)
  4. cellular communications by receptor proteins & hormonal proteins (ex: insulin)
  5. movement by contractile & motor proteins (ex: actin, myosin)
  6. defense against foreign substances (immune response) by defensive proteins (ex: antibodies)
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45
Q

Enzymes - type of protein

A

that acts as a catalyst, speeding up chemical reactions

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46
Q

Polypeptides: Amino Acid Polymers

A
  • monomer - amino acid (each polypeptide has a unique linear sequence of amino acids)
  • protein consists of one or more polypeptides
  • aminoacids => polypeptides => proteins
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47
Q

Amino acid monomer:

A
  • organic molecules possessing both carboxyl and amino groups
  • differ in their properties due to differing side chains, called R groups
  • general structure: H2N-CHR-COOH
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48
Q

Glycine

A

Gly

nonpolar

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49
Q

Alanine

A

Ala

nonpolar

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50
Q

Valine

A

Val

nonpolar

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51
Q

Leucine

A

Leu

nonpolar

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52
Q

Isoleucine

A

Ile

nonpolar

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53
Q

Methionine

A

Met

nonpolar

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54
Q

Phenylalanine

A

Phe

nonpolar

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55
Q

Tryptophan

A

Trp

nonpolar

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56
Q

Proline

A

Pro

nonpolar

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57
Q

Serine

A

Ser

polar

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58
Q

Threonine

A

Thr

polar

59
Q

Cysteine

A

Cys

polar

60
Q

Tyrosine

A

Tyr

polar

61
Q

Asparagine

A

Asn

polar

62
Q

Glutamine

A

Gln

polar

63
Q

Glutamine

A

Gln

64
Q

Aspartic acid

A

Asp

negatively charged

65
Q

Glutamic acid

A

Glu

negatively charged

66
Q

Lysine

A

Lys

positively charged

67
Q

Arginine

A

Arg

positively charged

68
Q

Histidine

A

His

positively charged

69
Q

Nonpolar molecules (9):

A

Grandma Always Visits London In May F(Ph)or Party Time

Glycine (Gly)
Alanine (Ala)
Valine (Val)
Leucine (Leu)
Isoleucine (Ile)
Methionine (Met)
Phenylalanine (Phe)
Proline (Pro)
Tryptophan (Trp)

70
Q

Polar molecules (6):

A

Santa Took Candy After Going snowballTHrowing

Serine (Ser)
Tyrosine (Tyr)
Cysteine (Cys)
Asparagine (Asn)
Glutamine (Gln)
Threonine (Thr)

71
Q

Electrically charged (5):

A

Aspartic acid (Asp)
Glutamic acid (Glu)
Lysine (Lys)
Arginine (Arg)
Histidine (His)

72
Q

Polypeptides are linked by:

A

covalent bonds called peptide bonds

73
Q

Four Levels of Protein Structure:

A

• Primary structure: the unique sequence of amino acids
• Secondary structure: consists of coils and folds in the polypeptide chain (α-helices and β-pleated sheets linked by H-bonds)
• Tertiary structure: the 3-dimensional structure (shape) of a protein determined by the interactions among various side chains (R groups linked by van der Waals interactions, H-bonds, ionic bonds, disulfide bridges)
• Quaternary structure: results when a protein consists of multiple polypeptide chains (subunits)

74
Q

Tertiary structure: types of interactions (5):

A

• Disulphide bonds - covalent bonds b/w 2 -SH groups in cysteine
• Hydrogen bonds
• van der Waals interactions
• Electrostatic interactions (ionic bonds)
• Hydrophobic interactions

75
Q

Chaperones (chaperonins) -

A
  • proteins that assist and maintain the proper folding of other proteins
  • wherever there are ribosomes: cytosol (free ribosomes synthesize cytosolic proteins), mitochondria, chloroplasts, rough ER (bound ribosomes synthesize secreted & membrane-bound proteins).
76
Q

Sickle-Cell Disease:

A

Example of a disease caused by simple change in primary structure:

Glu (- charged) substitutes f/ Val (nonpolar) => crystallization of hemoglobin into fibers => sickle shape of blood cells => blood clotting

77
Q

Denaturation

A

the loss of a protein’s native conformation due to unravelling => loss of fn

denaturated protein is biologically inactive

renaturation - reverse of denaturation (sometimes possible, depends on how much damage to the structure is done)

78
Q

Protein denaturation factors:

A
  • pH changes
  • salt concentration changes
  • temperature changes
  • other environmental factors
79
Q

Nucleic acids’ fn:

A

store and transmit hereditary information

80
Q

genes

A
  • units of inheritance
  • program the amino acid sequence of polypeptides
  • made of DNA (monomer - nucleotide)
81
Q

2 types of nucleic acids:

A

– Deoxyribonucleic acid (DNA)
– Ribonucleic acid (RNA)

82
Q

Structure of nucleic acids

A
  • Each polynucleotide consists of monomers called nucleotides
  • Nucleotide = nitrogenous base + pentose sugar + phosphate group
  • Nucleoside = nitrogenous base + pentose sugar
83
Q

Nitrogenous bases in nucleotides

A

Pyrimidines:
- cytosine, thymine (DNA), uracil (RNA)

Purines:
- adenine, guanine

84
Q

Sugars in nucleic acids:

A

deoxeribose
ribose

85
Q

What ends does each DNA strand have?

A
  • phosphate 5’-end
  • -OH 3’-end
86
Q

nucleotides are connected with a covalent bond to create a polymer (name of bond)

A

phosphodiester bond (the–OH group on the 3´ carbon of one nucleotide is linked to the phosphate on the 5´ carbon on the next nucleotide)

87
Q

Cellular DNA molecules consist of

A

2 antiparallel polynucleotide strands that form a double helix

Strands are antiparallel: each strand runs in an opposite direction to the other one: one runs 5’→3’ and the other 3’→5’

88
Q

Double helix is connected by:

A

nitrogenous bases in DNA form hydrogen bonds in a complementary fashion:
A-T
G-C

89
Q

Microscopy is used f/ studying

A

cell structure & morphology

90
Q

Cell fractionation is __ and is used f/ studying__

A
  • isolation of subcellular structures
  • f/ studying cell function
91
Q

Light microscopes (LM) principle of work:

A

– Visible light passes through a specimen
– Magnification of cellular structures using lenses

92
Q

Electron microscopes (EM) principle of work:

A

Focus a beam of electrons through a specimen (TEM) or onto its surface (SEM) by applying a
strong magnetic field

93
Q

What can be seen w/ light microscope:

A

objects from 1 mm to 200 nm (most plant & animal cells, nucleus, most bacteria, mitochodrion)

We CAN’T see: smallest bacteria, viruses, ribosomes, proteins, lipids, atoms

94
Q

Comparison of the size of cellular and acellular forms of living organisms

A

Virus 0.05 μm < Phage 0.1 μm < Bacterium (0.1 - 10 μm) < Eukaryotic cell (10-100 μm)

95
Q

Magnification

A

ratio of an object’s image size to its real size

96
Q

Resolution

A

measure of the clarity of the image (minimum distance of two distinguishable points)

97
Q

Contrast

A

visible differences in parts of the sample

98
Q

5 types of LM

A
  1. Brightfield
  2. Phase-contrast
  3. Differential-interference-contrast (Nomarski)
  4. Fluorescence
  5. Confocal
99
Q

Brightfield

A

1a - unstained specimen: Passes light directly through specimen. Unless cell is naturally
pigmented or artificially stained, image has little contrast.
1b - stained specimen: Staining with various dyes enhances contrast, but most staining procedures require that cells be fixed (preserved)

result is 2D

100
Q

Phase-contrast

A

Enhances contrast in unstained cells by amplifying variations in density within specimen;

especially useful for examining living unpigmented cells (e.g. dividing cells).

results is 2D

101
Q

Differential-interference-contrast (Nomarski)

A

Like phase-contrast microscopy, it uses optical modifications to exaggerate differences in density, making the image appear almost 3D, but result is still 2D

102
Q

Fluorescence

A

Shows the locations of specific molecules in the cell by tagging the molecules with fluorescent dyes or antibodies. These fluorescent substances absorb ultraviolet (UV) radiation and emit visible light

result is 2D

103
Q

Confocal

A

Uses lasers and special optics for “optical sectioning” of fluorescently-stained specimens. Only a single plane of focus is illuminated; out-of-focus fluorescence above and below the plane is subtracted by a computer.

result is 3D

104
Q

Two types of EM:

A
  1. Transmission electron microscope (TEM): focus a beam of electrons through a specimen => used mainly to study the internal structure of cells. Result is 2D
  2. Scanning electron microscope (SEM): focus a beam of electrons onto the surface of a specimen => used to study of the surface of the specimen. Result is 3D
105
Q

Cell fractionation:

A
  • enables isolation of subcellular components and determination of the organelle functions
  • fractionates cells and separates the major organelles from one another, based on size and density
106
Q

Centrifugation

A

used to fractionate cells into their component parts (e.g. ultracentrifuges)

107
Q

Differential vs Density gradient centrifugation

A

Differential centrifugation:
- stabilizing solvent gradient (stable solvent C; e.g. 0.5 M sucrose)
- multiple centrifugation steps (increasing acceleration and time)
-separation is based on size

Density gradient centrifugation:
- steep solvent C
- single centrifugation step
- separation is based on Density (size & shape)

108
Q

Which cells appeared firs and what’s the time diff b/w the two?

A

Prokaryotic =>109 years=> eukaryotic

109
Q

All cells have several basic features in common (4):

A

– bounded by a plasma membrane
– contain a semifluid substance called the cytosol
– contain chromosomes
– have ribosomes

110
Q

Prokaryotic cells (3 characteristics):

A

– Do not contain a nucleus (no nuclear membrane)
– Have their DNA located in an unbound region called the nucleoid
– Do not have any membrane-bound organelles

111
Q

Eukaryotic cells (3 characteristics):

A

– Contain a nucleus bounded by a membranous nuclear envelope
– Generally bigger than prokaryotic cells (10-100 times)
– have internal membranes that compartmentalize their functions (e.g. ER, Golgi) and membrane-bound organelles (e.g. mitochondria, chloroplasts)

112
Q

Structures common f/ all prokaryotic cells (3):

A
  • Nucleoid: region where the cell’s DNA is located (not enclosed by a membrane)
  • Ribosomes: organelles that synthesize proteins
  • Plasma membrane: membrane enclosing the cytoplasm
  • Cell wall: rigid structure outside the plasma membrane
113
Q

Structures common only f/ some prokaryotic cells:

A
  • Pili: attachment structures on the surface of some prokaryotes
  • Capsule: jelly-like outer coating of many prokaryotes
  • Flagella: locomotion structure of some bacteria
114
Q

nucleolus in nucleus of eukaryotic cells is responsible f/

A

r-RNA synthesis

115
Q

Golgi complex vs ER in the pictures: how to differentiate?

A

Golgi: faces plasma membrane and ER
ER: faces Golgi and nucleus

116
Q

Cytoplasm

A

region b/w the plasma membrane and nucleus => includes all the subcellular structures except the nucleus

117
Q

Cytosol

A

intracellular fluid component of cytoplasm => excludes organelles and other subcellular membranes, contains ribosomes, proteasomes, cytoskeletal filaments, soluble molecules, and water

118
Q

Plant cells (4) vs Animal cells (3):

A

Plant cells have:
- Chloroplasts
- Central vacuoles (instead of lysosomes)
- Cell wall
- Different cell junctions (plasmodesmata)

Animal cells have :
- Lysosomes
- Centrosome (composed of centrioles)
- Some have a flagella (e.g. sperm cell)

119
Q

Plasma membrane (Cytoplasmic membrane)

A
  • selective barrier that allows sufficient passage of oxygen, nutrients, and waste in and out of the cell
  • consists of phospholipid bilayer
  • semi-permiable
120
Q

The Nucleus

A
  • contains most of the DNA in eukaryotic cell
121
Q

chromatin

A
  • complex of proteins and DNA
  • condensation of chromatin => discrete chromosomes
122
Q

Central dogma of transfer of genetic information:

A

DNA =>transcription=> mRNA =>translation=> protein

transcription - in nucleus
translation - in cytoplasm

123
Q

What processes take place in the nucleus?

A
  • DNA is replicated before every cell division (in nucleus)
  • DNA is transcribed to mRNA in the nucleus
124
Q

Nucleolus

A
  • denser area in the nucleus
  • here ribosomal rRNA is synthesized, it after is assembled w/ proteins => subunits exit the nucleus & form ribosomes in the cytoplasm
125
Q

Ribosomes:

A

– particles made of ribosomal RNA (rRNA) and protein
– consist of a small and a large subunit which are assembled in the nucleolus
– fn: translation - protein synthesis
– 2 cellular locations: free ribosomes in cytosol => cytosolic proteins, bound ribosomes in RER => secreted or membrane-bound proteins

126
Q

ER:

A
  • Network of membranous tubules and sacs
  • Inside space - lumen
  • ER membrane: continuous with the nuclear envelope
  • 2 distinct regions: smooth ER, rough ER
127
Q

SER (fns: 4)

A
  • doesn’t have any bound ribosomes
    Fns:
  • Synthesizes lipids
  • Metabolizes carbohydrates
  • Stores calcium
  • Detoxifies poisons
128
Q

RER fns (3):

A
  • has bound ribosomes
    Fns:
  • synthesis of secreted proteins or membrane-bound proteins
  • Some post-translational modifications
  • Protein targeting (sorting): transports and distributes proteins to other cell compartments (e.g. Golgi) by producing membrane-bound transport vesicles (cell trafficking)
129
Q

Post-translational modifications that occur in the RER (4):

A
  • Polypeptide cleavage: some polypeptides are activated by enzymes that cleave them in order to become functional (ex: insulin)
  • Protein folding (tertiary structure): e.g. disulphide bond formation.
  • Subunit assembly (protein quaternary structure): Some polypeptides come together to form the subunits of a functional protein (ex: haemoglobin)
  • Some chemical modifications: addition of chemical groups to proteins (e.g. glycosylation, hydroxylation) => formation of glycoproteins (some in RER but most in Golgi apparatus).
130
Q

The Golgi Apparatus

A
  • Consists of flattened membranous sacs (cisternae)
  • TGN (trans Golgi network) faces the PM
  • CGN (cis Golgi network) faces the ER
  • transfers the vesicles that it receives from RER
131
Q

Fns of the Golgi Apparatus (3):

A
  1. Protein and macromolecule processing (chemical modifications): Receives and modifies protein and other macromolecule products of the ER by addition of chemical groups to proteins (e.g. glycosylation, phosphorylation, hydroxylation => production of glycoproteins, glycolipids, lipoproteins)
  2. Macromolecule sorting and targeting: Sorts and packages biomolecules into transport vesicles and sends them to other parts of the cell or the organism (targeting= transport to their cellular destination)
  3. Manufacture of certain macromolecules ex: polysaccharides
132
Q

Proteins
Lipids
Carbs
are produced in which structures of the cell?

A

Proteins - RER
Lipids - SER
Carbs - Golgi

133
Q

Lysosomes -

A
  • membranous vesicles containing hydrolytic enzymes, which function at pH=4
134
Q

Fns of lysosomes:

A
  1. digestion of macromolecules (or even microorganisms)
    - phagocytosis: intracellular digestion, human macrophages use lysosomes to ingest pathogenic microorganisms (immune cells)
    - autophagy: destruction of damaged organelles, recycling of cell’s organic material
  2. recycling: release simple sugars, aminoacids, nucleotides and FA to be reused by the cell for building new macromolecules
135
Q

Types of vacuoles (3):

A
  • Food vacuoles (phagosomes): formed by phagocytosis
  • Contractile vacuoles: pump excess water out of protist cells (ex: Paramecium)
  • Central vacuole: in plant cells
136
Q

The endomembrane system function (3):

A
  • important role in the cell’s compartmental organization
  • regulates protein traffic (trafficking)
  • performs metabolic functions in the cell
137
Q

Endomembrane system components:

A

– Nuclear envelope
– Endoplasmic reticulum
– Golgi apparatus
– Lysosomes/vacuoles
– Plasma membrane

• Components are either continuous or connected via vesicle-mediated transfer

138
Q

Semi-independent organelles:

A

mitochondria & chloroplasts
- not part of endomembrane system
- have a double membrane
- contain their own DNA (circular double -stranded mtDNA)
- their proteins are made by their own free ribosomes (in mitochondrial matrix and chloroplast stroma)

139
Q

Mitochondria and chloroplasts fn:

A
  • change energy from one form to another

mitochondria:
- sites of cellular respiration
- found in nearly all eukaryotic cells (both animal & plant)

chloroplasts:
- sites of photosynthesis
- only found only in plant cells and algae

140
Q

Plastids

A

plant organelles:

  • Chloroplasts: contain chlorophyll
  • Chromoplasts: contain other pigments (e.g. carotenoids)
  • Amyloplasts (leucoplasts): contain starch granules
141
Q

Peroxisomes and their fns (3):

A
  • specialized membrane-bound metabolic compartments

Fns:
1. produce hydrogen peroxide (H2O2) and convert it to H2O by their enzymes (catalase and oxidase)
2. Detoxification: e.g. liver peroxisomes detoxify alcohol and other harmful compounds
3. FA breakdown (β-oxidation of very long fatty acids)

142
Q

Proteasomes and their fns:

A
  • giant protein complexes that bind to protein molecules and degrade them

Fn - protein degradation of short-lived cytosolic proteins & non-functional (misfolded) proteins: these are attached to ubiquitin (ubiquitination) => targeted to the proteasome f/ degradation in order to be recycled

143
Q

Where are long-lived proteins degraded?

A

in lysosomes

144
Q

Resolution of microscopes:

A

LM - 200 nm
EM - 2 nm

the lower the resolution - the higher the magnification

Biology 103 1 sem (8 decks)

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