Piv txwv ntawm Cov Lus Nug thiab Kev Sib Tham txog Organic Macromolecules
Cov organic macromolecules yog cov molecules loj heev thiab nyuaj uas ua lub luag haujlwm tseem ceeb hauv ntau yam txheej txheem ntawm lub cev. Cov organic macromolecules uas paub zoo tshaj plaws suav nrog cov carbohydrates, lipids, proteins, thiab nucleic acids. Hauv tsab xov xwm no, peb yuav tham txog ntau qhov piv txwv ntawm cov teeb meem thiab lawv cov kev sib tham txog cov organic macromolecules.
1. Cov Khoom Noj Uas Muaj Carbohydrate
Lo lus nug thib 1
Ib lub molecule disaccharide yog tsim los ntawm ob lub glucose monosaccharides. Yog tias qhov hnyav molecular ntawm glucose yog 180, qhov hnyav molecular ntawm disaccharide no yog dab tsi?
Kev Sib Tham 1
Cov disaccharides raug tsim los ntawm kev sib xyaw ua ke uas tsim cov glycosidic bond thiab cov dej molecule. Qhov hnyav molecular ntawm ib lub glucose molecule yog 180. Yog li ntawd, ob lub glucose molecule yuav muaj qhov hnyav molecular ntawm:
\( 180 \, \text{u} + 180 \, \text{u} = 360 \, \text{u} \)
Txawm li cas los xij, thaum lub sijhawm tsim cov disaccharide, ib lub molecule dej (H₂O) yuav raug tso tawm. Qhov hnyav molecular ntawm dej yog 18 u.
Yog li, qhov hnyav molecular (Mr) ntawm disaccharide yog:
\( 360 \, \text{u} – 18 \, \text{u} = 342 \, \text{u} \)
Qhov no txhais tau hais tias qhov hnyav molecular (Mr) ntawm disaccharide yog 342.
2. Cov roj (lipids)
Lo lus nug thib 2
Cov roj (lipids) muaj lub luag haujlwm hauv lub cev ua lub zog. Yog tias ib lub molecule triglyceride tsim tau 9 calories ntawm lub zog rau ib gram, 5 grams ntawm triglyceride tsim tau lub zog ntau npaum li cas?
Kev Sib Tham 2
Lub zog uas ib gram ntawm triglycerides tsim tawm yog 9 calories. Yog li ntawd, lub zog uas 5 grams ntawm triglycerides tsim tawm tuaj yeem suav los ntawm kev muab tus lej ntawm triglycerides hauv grams los ntawm lub zog ib gram:
\[ \text{Zog} = 5 \, \text{gram} \times 9 \, \text{calories/gram} \]
\[ \text{Zog} = 45 \, \text{calories} \]
Yog li, 5 grams ntawm triglycerides muab 45 calories ntawm lub zog.
3. Kev Cuam Tshuam
Lo lus nug thib 3
Sau npe thiab piav qhia txog peb theem ntawm cov qauv protein uas muaj ua ntej mus txog cov qauv tertiary.
Kev Sib Tham 3
Cov protein muaj cov qauv nyuaj heev uas tuaj yeem piav qhia ntawm ntau theem, uas yog:
1. Cov Qauv Tseem Ceeb
- Cov qauv tseem ceeb yog cov kab sib law liag ntawm cov amino acids hauv ib qho polypeptide. Cov kab sib law liag no txiav txim siab ncaj qha rau cov yam ntxwv thiab kev ua haujlwm ntawm cov protein uas tshwm sim.
– Piv txwv: cov amino acid sequence methionine-serine-valine-alanine.
2. Cov Qauv Thib Ob
- Cov qauv theem ob yog cov qauv ruaj khov thiab tsis tu ncua ntawm kev sib txuas lossis kev quav ntawm cov saw polypeptide. Cov qauv no suav nrog cov qauv xws li alpha helices (α-helices) thiab beta-fold sheets (β-sheets).
- Cov qauv no tau ruaj khov los ntawm cov hydrogen bonds ntawm cov atoms hauv polysaccharide backbone.
3. Cov Qauv Qib Peb
- Cov qauv Tertiary yog qhov txuas ntxiv coiling thiab folding ntawm cov saw polypeptide uas tsim cov qauv tridimensional nyuaj.
- Cov qauv tertiary raug ruaj khov los ntawm ntau hom kev sib cuam tshuam, suav nrog cov hydrogen bonds, hydrophobic interactions, disulfide bridges, thiab ionic interactions ntawm amino acid side chains.
Thaum cov qauv tertiary raug tsim, qee cov protein kuj tuaj yeem tsim cov qauv quaternary qhov twg ntau cov saw polypeptide sib xyaw ua ke los tsim ib qho qauv ua haujlwm.
4. Cov kua qaub nucleic
Lo lus nug thib 4
DNA kho tau qhov puas tsuaj los ntawm lub teeb UV li cas thiab lub luag haujlwm ntawm cov enzymes hauv cov txheej txheem no yog dab tsi?
Kev Sib Tham 4
Kev puas tsuaj ntawm DNA los ntawm lub teeb UV feem ntau ua rau muaj cov thymine dimers, uas yog cov kev sib txuas tsis zoo ntawm ob lub hauv paus thymine uas nyob ib sab hauv ib txoj DNA. Cov txheej txheem kho qhov kev puas tsuaj no feem ntau yog ua los ntawm lub tshuab kho nucleotide excision (NER).
Cov theem ntawm kev kho DNA vim yog kev puas tsuaj ntawm UV yog:
1. Kev Tshawb Pom Kev Puas Tsuaj
- Cov enzymes tshwj xeeb uas nrhiav tau pom cov kev hloov pauv hauv cov qauv DNA uas tshwm sim los ntawm thymine dimers.
2. Kev Txiav Tawm Kev Puas Tsuaj
- Endonucleases txiav cov DNA ntu nyob ib puag ncig thaj chaw puas tsuaj, tshem tawm cov ntu uas muaj thymine dimers.
3. DNA rov tsim dua tshiab
- DNA polymerase ua kom tiav qhov sib txawv uas tsim los ntawm kev siv cov xov sib txuas ua tus qauv los tsim ib ntu DNA tshiab.
4. Pab Koomtes
- DNA ligase ces koom nrog cov DNA tshiab uas tau tsim los rau DNA uas twb muaj lawm, rov qab kho qhov kev ncaj ncees ntawm cov qauv DNA.
Cov txheej txheem no ua kom ntseeg tau tias cov ntaub ntawv caj ces tseem nyob ruaj khov thiab tuaj yeem xa mus rau qhov raug thaum lub sijhawm rov ua dua ntawm tes.
5. Kev Tshawb Fawb Txog Cov Organic Macromolecules
Lo lus nug thib 5
Kev kuaj hauv chav kuaj siv cov tshuaj Benedict los kuaj seb puas muaj ib hom carbohydrate tshwj xeeb. Qhov kev ua haujlwm no ua haujlwm li cas, thiab yuav pom cov txiaj ntsig dab tsi yog tias muaj cov carbohydrate no?
Kev Sib Tham 5
Cov tshuaj Benedict siv los sim seb puas muaj cov suab thaj txo qis, xws li glucose thiab fructose. Cov suab thaj txo qis muaj ib pawg aldehyde lossis ketone dawb uas tuaj yeem txo cov ions tooj liab (II) hauv Benedict cov tshuaj rau cov ions tooj liab (I). Qhov kev tshuaj tiv thaiv no ua rau muaj kev hloov xim uas tuaj yeem pom tau los ntawm kev pom.
Cov txheej txheem thiab cov txiaj ntsig uas tuaj yeem pom hauv qhov kev xeem Benedict yog:
1. Ntxiv Benedict's Solution
– Cov kua xiav Benedict raug ntxiv rau cov kua qauv carbohydrate thiab cov khoom sib tov raug cua sov.
2. Kev Hloov Xim
– Yog tias muaj cov suab thaj txo qis, cov tshuaj yuav hloov xim ntawm xiav mus rau ntsuab, daj, txiv kab ntxwv, lossis liab cib, nyob ntawm seb cov suab thaj txo qis ntau npaum li cas.
- Xim ntsuab qhia txog qhov concentration qis ntawm cov suab thaj txo qis.
- Xim liab cib qhia tias muaj cov suab thaj ntau heev.
Cov tshuaj tiv thaiv no tso cai rau kev yooj yim thiab ncaj qha nrhiav tau cov suab thaj txo qis hauv cov qauv tshuaj lom neeg.
Xaus
Cov organic macromolecules xws li carbohydrates, lipids, proteins, thiab nucleic acids ua lub luag haujlwm tseem ceeb hauv cov kab ke ua neej. Kev nkag siab txog lawv cov qauv, kev ua haujlwm, thiab yuav ua li cas los txheeb xyuas thiab kho lawv yog qhov tseem ceeb hauv ntau qhov kev tshawb fawb, tshwj xeeb tshaj yog biology thiab biochemistry. Cov piv txwv thiab kev sib tham saum toj no yuav muab kev nkag siab tob dua txog cov organic macromolecules thiab lawv cov ntawv thov hauv lub neej txhua hnub.
