Cells, Biological Molecules, Membranes, Enzymes (2) Flashcards

Question

what are the functions of Ca(2+), potassium K(+) and sodium Na(+) ions

Answer 1

Ca(2+) calcium ions nerve impulse transmission, muscle contraction Na(+) sodium ions nerve impulse transmission, kidney function K(+) potassium ions nerve impulse transmission, stomatal opening

Answer 2

they are soluble and have the general formula (CH2O)n where n is = or \>3.

Answer 3

***p**rimary*- **peptide** * secondary*- **intra**molecular **hydrogen** bonds * tertiary*- **hydrogen** (weakest), **ionic** (form between oppositely charged R-groups), **disulfide/covalent** (bonds or bridges, strongest of all, only form between S-containing R-groups), **hydrophobic/hydrophilic interactions** (weak, between polar and non-polar R-groups) * quaternary*- " as tertiary: *hydrogen, ionic, disulfide/covalent, hydrophobic/hydrophilic interactions*

Answer 4

dilute the unknown eg. serial dilution, and then calculate the original eg. multiply.

Answer 5

_H⁺ hydrogen ions_ catalysis of reactions, pH determination, chemiosmosis _NH₄_⁺ _ammonium ions_ production of nitrate ions by bacteria

Answer 6

cells that can differentiate into ALL types of cell

Answer 7

1. acrosome at top of head, contains hydrolytic enzymes to digest outer layers of ovum follicle to reach cytoplasm/nucleus. 2. head contains haploid nucleus (n) for fertilisation of an ovum for subsequent production of diploid zygote (2n). 3. midpiece contain large quantity of mitochondria to produce ATP by AR to provide energy for tail motion 4. tail: flagellum/undulipodia contains contractile microtubule fibres to enable movement/swimming

Answer 8

micrometers (um)

Answer 9

collagen molecules form staggered COVALENT CROSS LINKS with each other, forming more chains. Collagen molecules wrapped around each other from COLLAGEN FIBRILS (and then collagen fibres)

Answer 10

* OH^- hydroxide ions* **catalysis of reactions**, **pH determination** * Cl^- chloride ions* balance the **positive charge** of **sodium and potassium ions** in cells

Answer 11

a carboxyl group (--COOH attached to carbon skeleton) and an amine group (NH2 attached to carbon skeleton, a H attached to the C and a variable R-group attached to the C. The different R-groups result in different amino acids (of which there are 20).

Answer 12

the absorption and re-radiation of light

Answer 13

-anchor the nucleus -allow cell to cell signalling eg. antigens, WBCs, ECM -allow cell to cell adhesion in tissues

Answer 14

C3 H6 O5 = triose. eg. TP/GP in Calvin cycle/glycolysis

Answer 15

the interior of cells is often transparent staining allows **different components of cells to be distinguished between** **provides contrast between structures**

Answer 16

The **hydrophilic polar 'head'** and the **hydrophobic nonpolar 'tail'**

Answer 17

the **descendants of totipotent** cells they can **differentiate** into cells derived from the three germ layers of *endoderm, mesoderm, ectoderm* *eg. ectoderm can differentiate into skin, nerves, hair*

Answer 18

the resolution can be **no greater than 0.2µm**, because that is **half the wavelength** (*400nm/0.4µm*) of **visible** light. ## Footnote *Light waves can resolve objects greater than or equal to 400nm apart.*

Answer 19

increasing TEMPERATURE to increase kinetic energy, causing the bonds to vibrate and not maintain the shape of the protein and eventually break (they are not covalent so not very strong). Once it has lost its shape, a protein is DENATURED.

Answer 20

_TOTIPOTENT stem cells_

Answer 21

an insoluble fibrous protein

Answer 22

P = insoluble, granular S = polysaccharide, branched TOB = a-1,4 glycosidic bonds and a-1,6 glycosidic bonds, intramolecular H-bonds FI = chloroplasts (as starch granules) tubers, storage organs F = energy store in plants

Answer 23

a covalent bond is formed between two amino acids, removing the OH from the amine group and the H from the carboxyl group during the condensation reaction. the reaction is catalysed by peptidyl transferase

Answer 24

Ca²⁺ calcium ions K+ potassium ions Na⁺ sodium ions H⁺ hydrogen ions NH₄⁺ ammonium ions

Answer 25

_CELLS:_ **erythrocytes (RBCs** **neutrophils (WBCs** **sperm cells** **muscle cells** _TISSUES:_ **cartilage** **epithelial tissues; single or multiple sheets of cells covering internal and external surfaces of organs and lining tubes eg. squamous epithelia, ciliated epithelia**

Answer 26

1. Lipids are soluble in alcohol but not water. The emulsion test dissolves any present lipids in ethanol, then adds water, causing the lipid to form a precipitate/emulsion. 2. Ethanol followed by distilled water are added to the samples. A piece of black paper is placed behind the sample to view the precipitate more clearly. 3. Mash the sample, allow solid to settle at the bottom of the tube, pipette the ethanol into a new test tube, add distilled water, use black paper.

Answer 27

it gives strength, shape, support and movement within the cell. It is made of intercellular proteins: microfilaments, intermediate filaments and microtubules.

Answer 28

lactose- sugar found naturally in milk

Answer 29

bone, cartilage, connective tissue formation prevents blood from bursting artery walls at high pressures

Answer 30

_NO₃_^- _nitrate ions_ nitrogen supply to plants for AA and protein synthesis _HCO₃_^- _hydrogen carbonate ions_ maintenance of blood pH _PO₄_^3- _phosphate ions_ cell membrane formation, nucleic acid and ATP formation, bone formation

Answer 31

Cl^- chloride ions HCO₃^- hydrogen carbonate ions OH^- hydroxide ions PO₄^3- phosphate ions NO₃^- nitrate ions

Answer 32

the unit of all living organisms

Answer 33

the induced fit hypothesis states that the active site is NOT exactly complementary in shape to the substrate. The substrate induces a change in the shape of the active site so that it can be complementary and the enzyme reverts back to the original shape after the reaction.

Answer 34

4. DENSITY OF ICE LOWER THAN DENSITY OF WATER; below 4'C, the molecules of H2O are further apart and therefore contains fewer molecules than an equal volume of liquid water, in a crystalline structure where each molecules is H-bonded to 6 neighbouring molecules. Therefore the ice floats, creating a barrier for the aquatic environment(insulation). -habitat: aquatic animals resist extreme cold and artic animals have a habitat on the surface -transport medium: density changes circulates nutrients 5. HIGH COHESIVE FORCES transport medium: as water is pulled up through the roots and xylem vessels due to evaporation from the leaves of the plant, the cohesive forces from H-bonds hold the column of water together within the cells. 6. STRONG SURFACE TENSION -habitat: collective strength of H-bonds between water molecules allow organisms to live on the surface eg. the water strider. 7. ADHESIVE FORCES -transport medium: as water is pulled up through the roots and xylem vessels due to evaporation from the leaves of the plant, adhesive forces of water to the cell walls help resist the downward force of gravity.

Answer 35

in adult stem cells eg. in the bone marrow they are present in the adult body and developing embryo in the cambium of the plant, to form xylem and phloem

Answer 36

1. **K+ is pumped** into **guard** cells. 2. **H2O** follows in by osmosis 3. guard cells become **turgid** 4. cells move **outwards** and the pore is opened (*reverse occurs when pores closing)*

Answer 37

**more glucose = more Cu₂₊O precipitate** ## Footnote and therefore **less copper sulfate(CuSO₄)**, leading to a **lower intensity of blue colouration in the solution**, and tf **more red light transmitted through** the solution.

Answer 38

**maltose** produced from hydrolysis of amylose found in germinating seeds

Answer 39

a hydrogen atom bonded to an oxygen atom, which bonds to the carbon skeleton (---OH) found in all saccharides, and ethanols, (glycerol!) alcohol is the name of their compounds

Answer 40

_CELLS:_ **root hair cells** **leaf cells: palisade and guard cells** _TISSUES:_ **of the transport system: xylem and phloem**

Answer 41

*transmission electron microscope TEM* tissue/cell is infiltrated with resin, cut into very thin slices- diamond knife beam of electrons is passed through slice of material where **electrons are absorbed = dark** where **electrons come through = white** ***image has 2D flat appearance*** ***objects can be magnified more than 500,000x*** ***TEM has the highest degree of resolution (no figure needed)***

Answer 42

PROTEASES- water molecule used to break peptide bonds in a hydrolysis reaction, to reform AAs

Answer 43

deoxyribose C5 H10 O4

Answer 44

the way in which the primary structure of a polypeptide chain folds eg. alpha-helices and beta-pleated sheets (held together by hydrogen-bonds)

Answer 45

Both are insoluble, branched and compact.

Answer 46

synthesis by condensation reaction- removal of H2O, formation of bond- example of anabolism

Answer 47

SKELETAL = muscles, attached to skeleton CARDIAC = in walls of the heart SMOOTH = in the walls of internal organs

Answer 48

* AIM: To find out whether a substance is present and at what concentration. Reducing sugars eg. glucose, reduce the Cu2+ in Benedict's reagent to Cu+ which causes a precipitate to form. One measures the concentration of Cu2+ remaining in solution using a colorimeter to become quantitative.* 1. **Serial dilution** of glucose eg. 1.00%, 0.50%, 0.25%, 0.13%, 0.06%. Control (Benedict's reagent + water) Unknown. 2. **Add Benedict's reagent**. Boil. 3. **Centrifuge** to remove suspended particles (Cu2+ precipitate) from solution, which are opaque and **would therefore scatter the light** creating a false low transmission reading. (not allowing transmission of light through the solution in the colorimeter) 4. **Set colorimeter to red light** and use **distilled water in a cuvette to set 100% transmission**. 5. **Repeat** for samples. Draw **calibration curve** to find unknown concentration of glucose.

Answer 49

1. globular/fibrous 2. prosthetic group/no prosthetic group 3. soluble/insoluble 4. four polypeptide chains/three

Answer 50

an atom or molecule which does not have equal proton and electron numbers eg. atom loses and electron, now has a net positive charge.

Answer 51

In the **mitochondria** of **eukaryotic** cells and the **cytoplasm** of **prokaryotic** cells.

Answer 52

A **hydrophobic sterol** that sits **between fatty acid chains within membranes** to regulate the **fluidity** of the phospholipid bilayer to be neither too rigid nor too fluid. (not **too fluid at high** temperatures by reducing phospholipid movement, not **too rigid at low** temperatures by hindering solidification as the phospholipids have less energy and more less)

Answer 53

a ^{_{single spot of focused light}} is moved across a specimen which has been dyed using a _fluorescent dye._ Light of a **longer wavelenth is emitted** and used to produce a magnified image.

Answer 54

the degree to which the size of an image is larger than the object itself

Answer 55

light is shone through the specimen/object to be viewed. Lab microscopes are compound; they have 2 lenses *objective lens* and *eyepiece lens _object is magnified twice_*

Answer 56

- as substrate concentration increases, there are more successful collisions -tf there are more occupied active sites, and more enzyme-substrate complexes made -rate of reaction increases up to the **optimum** concentration of substrate, where substrate concentration is no longer the **limiting factor** - *all active sites are occupied and all enzymes present are working at the maximum rate* = VMAX!! -tf increasing substrate concentration will no longer increase the rate of reaction, and the graph will plateau

Answer 57

P = highly insoluble, granular S = polysaccharide, highly branched TOB = a-1,4 glycosidic bonds and a-1,6 glycosidic bonds, intramolecular H-bonds FI = liver and muscle cells F = energy store in animals

Answer 58

1. DISULFIDE BONDS/BRIDGES: two cysteine amino acids found together, a strong double bond is formed between the sulfur atoms in the cysteine AAs (S===S) 2. IONIC BONDS. two oppositely charged R groups +ve and -ve form an ionic bond between them 3. HYDROGEN BONDS. 4. HYDROPHOBIC HYDROPHILIC BONDS. in a water-based environment, a globular protein will orientate itself such that the hydrophobic R groups are contained in the middle of the protein and the hydrophilic R groups are on the edges.

Answer 59

an enzyme that removes hydrogen from its substrate (oxidises it). H usually accepted by a co-enzyme to be used in

Answer 60

naturally found in fruit, sweeter than glucose, glucose is sweeter than galactose

Answer 61

1. embryonic stem cells derived from blastocysts (early embryo) 2. adult stem cells found in adult tissues eg. bone marrow 3. cord blood stem cells (also amniotic foetal stem cells) found in the umbilical cord 4. induced pluripotent stem cells which are multipotent or unipotent cells treated to be made pluripotent

Answer 62

DISSOLVING: PLANTS; Soil with **nitrates,** **cytosol** with nutrients in **aquatic** environments, **xylem** transports nutrients, **phloem** carries dissolved sucrose. ANIMALS; **water** in **blood plasma** allows transport of **hormones**, nutrients: *glucose, AAs, minerals, vitamins, waste substances: urea, carbon dioxide* HIGH LATENT HEAT OF EVAPORATION: sweating, panting, evaporation from the mucus membranes, transpiration HIGH COHESIVE FORCES: xylem

Answer 63

the degree to which it is possible to distinguish/separate between two objects close together *expressed as a measurement* ***HIGHER RESOLUTION = MORE DETAIL SEEN***

Answer 64

cells that can **produce only one cell type**, but have the property of **self-renewal** (which distinguishes them from non-stem cells) eg. mother cells of gametes

Answer 65

where one atom donates an electron to the other, forming pos+ and neg- ions held together by attraction of opposite charges

Answer 66

P = insoluble, water-permeable, **fibrous** S = polysaccharide, linear molecules parallel to each other TOB = B-1,4 glycosidic bonds, **inter**molecular H-bonds FI = plant cell walls F = structural, give strength to cell walls

Answer 67

* 1. ADV. LIGHT cheap to purchase vs. expensive to purchase* * 2. ADV. LIGHT natural colour can be observed vs. black and white* * 3. ADV. LIGHT material rarely distorted by prep. vs. may distort it and artefacts* * 4. ADV. LIGHT prep. is relatively quick, simple, cheap vs. requiring expertise, lengthy, complex equipment* * 5. ADV. LIGHT living material can be viewed vs. only dead due to vacuum* * 6. ADV. LIGHT small and portable vs. operated in special rooms* * 7. ADV. LIGHT unaffected by magnetic fields* **1. ADV. ELECTRON possible to see greater depth of field - SEM 3D images vs. restricted depth** **2. ADV. ELECTRON can resolve objects \<1nm or closer apart (constantly improving) vs. 0.2µm apart** **3. ADV. ELECTRON magnifies objects up to and beyond 500,000x vs. up to 1500x**

Answer 68

Transport and carry oxygen in the blood. The **haem group** contains an **Fe²⁺ ion**, onto which the oxygen molecules can **bind**.

Answer 69

ACTIN (protein) give the cell strength, support and keep the cell's shape allow cell movement eg. changing the shape of the cell; endo/exo-cytosis

Answer 70

in a phosphate group, where it is bonded to four oxygen atoms with a negative net charge, represented as PO4(-) it is part of the nucleotide, which is found in DNA, RNA. It is a component of energy-rich molecules such as ATP. Thirdly, it is bound to co-enzymes such as NADP/NADPH. It is the hydrophilic 'head' of phospholipids that make up the plasma membrane of cells.

Answer 71

y axis = % transmission of red light x axis = concentration of glucose

Answer 72

-as temp. increases, enzymes have more kinetic energy -more kinetic energy means there is more movement, increasing the likelihood of successful collisions -more molecules have enough energy to react -more enzyme-substrate complexes are made -more product is formed, increasing the rate of reaction -this increases until the optimum temperature is reached -after this point, all enzymes denature at roughly the same temperature

Answer 73

GLOBULAR AND FIBROUS. Globular protein tend to form spherical structures with hydrophobic R groups in the centre of the protein and hydrophilic R groups at the edges, meaning they are water-soluble. They have metabolic functions eg. enzymes in all organisms, plasma proteins and antibodies in mammals. Fibrous protein tend to form long fibres and mainly consist of repeated sequences of amino acids which are INSOLUBLE in water. They have structural functions eg. collagen in bone and cartilage, keratin in fingernails and hair.

Answer 74

They form cell walls in plant cells.

Answer 75

1. blood cells are made from multipotent haemopoietic adult stem cells in the bone marrow 2. the adult stem cells differentiate into all the different white blood cells LEUCOCYTES, red blood cells ERYTHROCYTES and PLATELETS.

Answer 76

1. HIGH TENSILE STRENGTH -strength of **covalent glycosidic bonds** between the B-glucose monomers, and between the parallel molecules of cellulose there is **intramolecular** **H-bonding**, which is collectively strong. 2. EXTRA SUPPORT FROM STRUCTURE- cellulose molecules bond in parallel lines by **intramolecular H-bonds** to form **microfibrils**. Microfibrils running in different directions make a **H-bonded** bundle = a **macrofibril**. 3. SUPPORT- there is **no** cytoskeleton 4. ALLOWS DIFFUSION OF WATER INTO CELLS as the cell wall is **fully permeable to water and ions** 5. PREVENT BURSTING when turgid, **turgidity** gives the cell **strength and support** 6. MACROFIBRILS **MIXED** dependent on function - *with lipids/cutin for waxy cuticle, suberin in roots and lignin in xylem walls* 7. ANIMALS DO **NOT** HAVE **CELLULASE ENZYME** to digest cellulose

Answer 77

P = soluble S = monosaccharide TOB = N/A FI = blood, tissue fluid, cells F = transport sugar in animals, ready source of energy

Answer 78

they are solid because the molecules can pack closely together because there are no kinks in the hydrocarbon 'tail'

Answer 79

a nitrogen atom bonded to two hydrogen atoms and the carbon skeleton found in amino acids amines is the compound name

Answer 80

-allow movement of organelles within the cells -form the spindle in mitosis, allowing movement of chromosomes to opposite poles of the dividing cell -make up cilia, flagella, centrioles, undulipodia

Answer 81

P = insoluble, granular S = polysaccharide, single chain, helical TOB = a-1,4 glycosidic bonds only, intramolecular H-bonds FI = chloroplasts (as starch granules) Tubers, storage organs F = energy store in plants

Answer 82

1. INSOLUBLE IN WATER- significant for animal cells that do **not** have a **cell wall**. Therefore water entering the cell would: 1. affect the **water potential** of the cell and 2. cause **osmotic swell** and eventual **cytolysis**. 2. MONOMERS EASILY HYDROLYSED- tf there can be a **rapid release** of energy, especially if **branched** like **amylopectin and glycogen**- the a-glucose monomers are hydrolysed by enzymes. 3. COMPACT- therefore they do **not** require a **large area** for storage, especially when **branched** like amylopectin and glycogen. They are **granular** i.e. they form dense granules in the cell; Starch forms in chloroplasts and glycogen mainly in the liver and muscle cells.

Answer 83

C6 H12 O6 = hexose. glucose, fructose, galactose. !structural isomers!

Answer 84

specimen is shadowed with a layer of metal and carbon it is **scanned by a fine electron beam, which is reflected from surface of specimen and transmitted to a detector** ***3D APPEARANCE*** ***objects can be MAGNIFIED 50,000x***

Answer 85

C5 H10 O5 = pentose. ribose, deoxyribose(c5h10o5), ribulose (as in ribulose 1-5 bisphosphate)

Answer 86

unsaturated hydrocarbon 'tails' of phospholipids cause kinks that prevent the molecules from packing too closely together. Fluid 'kinky' membranes are more likely to be found in ectotherms eg. fish in very cold water habitats, because it prevents rigidity. Viscous saturated membranes are more likely found in endotherms because they do not become as fluid and unstable.

Answer 87

CHONP -a pentose monosaccharide (5C atoms) -a phosphate group (PO4(2-)) an inorganic molecule, acidic, negatively charged -a nitrogenous base, a complex organic molecule with 1 or 2 C rings and N DNA has a negative net charge Nucleotides bond by condensation reactions to form a polynucleotide

Answer 88

**DEVELOPING EMBRYO** stem cells are able to differentiate into ALL of the specialised embryonic tissues **ADULT ORGANISM** stem cells act as a repair system for the body, replenishing specialised cells eg. bone marrow forming/replacing blood cells

Answer 89

polysaccharides- CHO, GLYCOSIDIC nucleic acids- CHONP, PHOSPHODIESTER proteins- CHONS, PEPTIDE fats/lipids- CHO (+P), ESTER

Answer 90

The phosphate group at carbon 5 interacts with the OH group at carbon 3 of the pentose sugar of an adjacent nucleotide, forming a PHOSPHODIESTER bond, leading to a strong covalently-bonded sugar-phosphate backbone

Answer 91

A *phosphorus* atom bonded to four oxygen atoms. One is double bonded, one bonds to carbon skeleton, two have negative charges. Found in **phospholipids, DNA, RNA, ATP, NADP** Name of compound is *organic phosphates*

Answer 92

polymers made of amino acid monomers/molecules

Answer 93

Form a covalent bond through a condensation reaction. The hydroxyl groups on the 1st and 4th carbons interact, forming a 1,4 glycosidic bond and a water molecule. This is now a disaccharide.

Answer 94

the number and sequence of amino acids that will form the polypeptide chain

Answer 95

it lowers the activation energy required for a reaction, i.e. the energy required for a reaction to commence. THE MINIMUM AMOUNT OF ENERGY REQUIRED FOR A SPECIFIC CHEMICAL REACTION TO OCCUR.

Answer 96

1. sometimes there are **artefacts** meaning the image is not accurate or is obscured 2. large **voltage** needed and a **vacuum** 3. **no colour, not 3D** 4.

Answer 97

a water soluble globular protein

Answer 98

glycogen, which is mainly stored in animals in the liver and muscle cells. Glycogen is more branched than amylopectin. Less space is required to store it. Glycogen is more compact and allows a quicker release of energy due to more free ends to add to or remove from. Therefore storing and release is faster during respiration. To release the glucose molecules, water is required for hydrolysis. Significance: animals are mobile

Answer 99

minerals/salts/ions (cations and anions)

Answer 100

they are produced from the fusion of an egg and a sperm into a zygote, which is a totipotent cell found in the morula, which is multiple totipotent cells

Answer 101

1. SCENT; contained in flowers to attract insects 2. SOURCE OF ENERGY; due to **long hydrocarbon chains (more reduced)** there is *_twice as much energy per g than carbohydrates or protein_*; helps animals who are *mobile*; helps small seeds because *seed dispersal* becomes easier 3. ENERGY STORAGE; for the equivalent amount of energy, *_fats have half the mass of proteins and carbohydrates_* 4. INSULATION; **bad conductor** of heat/ *reduces heat loss* 5. BUOYANCY; aquatic animals have large quantities of *subcutaneous fat* 6. PROTECTION; *_vital organs_* have 'padding', in particular the kidneys, heart 7. WATER PROOFING; eg. *waxy cuticle* on plants and insects

Answer 102

- **electron beam** is used instead of **light** - lenses are **magnets** - **resolution** of objects using an EM is **greater than LM,** therefore they can resolve objects much **smaller than a light microscope** - **smaller detail** can be seen using an EM than a LM

Answer 103

three polypeptide chains coiled around each other. Each chain is a coil, with hydrogen bonds between them, giving the structure more strength. (important because collagen is a STRUCTURAL PROTEIN)

Answer 104

**undifferentiated primal** cells common to **all multicellular organisms** they retain the ability to **renew** themselves via **cell division** they can **differentiate** into a wide range of different cell types, depending on their **potency**

Answer 105

a collection of organ systems, which is a collection of organs, which is a collection of several tissues carrying out the same general function, which are collections of the same specialised cells carrying out the same function, which are cells differentiated from stem cells * eg. in plants* * transport system making up part of the plant --\> vascular bundles make up transport system --\> root --\> root tissue --\> root hair cell*

Answer 106

they are strong and insoluble, therefore the cell does not 'drown'

Answer 107

in excess they are toxic to the body and cannot be stored. They are excreted from the body by deamination, which occurs in the liver of animals. Amino acids are converted to urea and removed from the body in the urine.

Answer 108

a globular biological catalyst protein, that speeds up the rate of a specific reaction and remains unchanged by that specific reaction, allowing it to efficiently speed up many reactions repeatedly.

Answer 109

yes. plants make all of the amino acids that they require for protein synthesis, the caveat being that they can acquire nitrates from the soil, which are converted to amine groups, and bonded to the products of photosynthesis. Humans must have proteins in their diet, which are broken down and then synthesised into the necessary proteins. 'Essential amino acids' are ones that cannot be formed from digested proteins and must be consumed directly.

Answer 110

**OPTICAL MICROSCOPES** light microscope laser scanning confocal microscope **ELECTRON MICROSCOPES** transmission electron microscope TEM scanning electron microscope SEM

Answer 111

it is formed from _chondrocytes_ (cartilage cells) within _connective tissue._ The condrocytes produce an _extracellular matrix of collagen fibres and elastic fibres._

Answer 112

1. DISSOLVES POLAR AND CHARGED SUBSTANCES -solvent: metabolic reactions can occur -transport medium: blood, xylem, phloem 2. HIGH SPECIFIC HEAT CAPACITY -habitat: stable environment for aquatic animals -thermostability for living cells 3. HIGH LATENT HEAT OF EVAPORATION -temperature regulation/coolant: large quantity of energy via radiation out of body to reduce body temp. especially for endotherms -stable environment for aquatic organisms

Answer 113

digestion by hydrolysis- addition of H2O, break down of bond- example of catabolism

Answer 114

Unsaturated fatty acids contain double bonds between carbon molecules (causing kinks in the hydrocarbon 'tail' of the molecule) Saturated molecules are linear, with no double bonds between C atoms. If the number of H is more than twice the number of C, it is saturated. eg. C15H31COOH vs C17H33COOH (Double bonding C atoms removes 2 hydrogen atoms' spaces)

Answer 115

-as pH increases, more successful collisions -more enzyme-substrate complexes are made, producing more product, increasing rate of reaction -this increases until the optimum pH level, around -after this point, the higher pH disrupts the ionic and hydrogen bonds -therefore the active site loses its tertiary structure and the shape is no longer complementary to the substrate -there are fewer enzyme-substrate complexes made, less product produced -the rate of reaction is lowered

Answer 116

the final 3D structure of a protein, entailing the shaping of the secondary structure, involving coiling or pleating, often with straight chains of amino acids in between

Answer 117

medicine, due to the ability of stem cells to differentiate into cells with certain **characteristics** through **cell culture** eg. after damage from burns, stem cells may be grown on biodegradable meshes to produce skin grafts very quickly and without the need to remove skin from another part of the body

Answer 118

1. SCENT 2. SOURCE OF ENERGY 3. ENERGY

Answer 119

The structure formed when two or more polypeptide chains (called subunits) join together, sometimes with an inorganic component eg. a haem group in haemoglobin PROSTHETIC GROUP, to form a protein. Subunits are not necessarily identical; enzymes are often two identical subunits, while insulin (hormone) has two different subunits. Bonds/interactions are the same as in tertiary structure, but between protein molecules.

Answer 120

an **artificial component that obscures the clear view of an anatomical structure,** often arising from the preparation of the specimen/slide.

Answer 121

Known collectively as starch, a chemical energy store in plants produced from photosynthesis . *Made of alpha-glucose monomers*. Amylose is **linear**. Amylose contains **only a-1,4 glycosidic** bonds. The angle of the bond causes it to form a **helical** structure, strengthened by **intramolecular H-bonds** within the molecule. Therefore it is more compact and a lot **less soluble** than the glucose molecules used to synthesise it. Amylopectin is **branched.** Amylopectin contains a-1,4 glycosidic bonds and **1,6 glycosidic bonds** between carbon 1 and carbon 6. Both have ***intramolecular H-bonds to hold helical structure.***

Answer 122

in embryonic stem cells taken from the blastocyst or embryo

Answer 123

P = soluble S = disaccharide (glucose + fructose) TOB = one a-1,4 glycosidic bond only FI = phloem F = transport sugar in plants

Answer 124

when many amino acids bond together by peptide bonds, catalysed by the enzyme peptidyl transferase present in ribosomes, the site of protein synthesis.

Answer 125

**cells differentiated from stem cells**

Answer 126

1. Light microscopes can resolve objects 0.2µm apart, whereas Electron microscopes have a much higher resolution than LM and LSCM (TEM has the highest)

Answer 127

Cellulose can be mixed with: ## Footnote * lipids/cutin for waxy cuticle* * suberin in roots* * lignin spiralled in xylem walls*

Answer 128

Mitochondria **1-4µm** Nucleoli Lysosomes Centrioles

Answer 129

HYDROPHOBIC interactions- *non-polar* regions are usually in the middle, having been excluded by the water surrounding them and as *hydrophilic* amino acids form *hydrogen bonds* with each other/the surrounding. IONIC bonds between *positively & negatively charged* amino acids. _Disulfide bridges_ are _covalent_.

Answer 130

A **fibrous** protein, a **triple helix**- very strong. Found in *connective tissue*. (quaternary structure = 3 subunits) Haemoglobin is **globular**, its quaternary structure is 4 subunits, each one with **a-helical** secondary structure. Conjugated proteins- each has prosthetic group = haem.

Answer 131

The *glycerol* loses **three OH** each *fatty acid* loses **HO** in its place there is an **O atom**

Cells, Biological Molecules, Membranes, Enzymes (2) Flashcards

(155 cards)