was discovered by Paul Ehrlich in 1891 - originally developed to
cells, it was discovered it was taken up selectively by different cells. It was marketed against
In 1932 it was discovered that
was effective against bacterial infections. The effective functional group was
Another drug containing this group is
which was used to cure Winston Churchill of pneumonia.
of an enzyme called
which is involved in the synthesis of
Sulfonamides do not kill bacteria but they are
The difficult stage of penicillin synthesis was
because it was susceptible to breaking in even slightly
conditions. Penicillin was first synthesised from a
reaction, using a reagent called
In industry a fungus called
synthesis penicillin through aerobic respiration.
Chanel no 5 was a landmark perfume because for the first time,
aldehydes were used. One of these aldehydes was
which is synthesized through a
Alarm pheromones are used to trigger a
response, for example by a guard bee from its sting chambers. For example,
is an alarm pheromone. Trail pheromones are
laid down by ants, each ant contains just
of trail pheromones.
Clavulanic acid is similar to penicillin in that it has a beta lactam ring. However, it is not effective as an antibiotic - it is used as a
Carbapenems are resistant to
and they are effective in both gram positive and negative bacteria. The
inhibitor of beta-lactamases.
Vancomycin inhibits an enzyme that forms
between peptidoglycan chains, this causes the cell wall to break down. Vancomycin resistance can arise when the final amino acid at the end of the
molecule changes, so vancomycin can no longer bind.
Daptomycin is a substitute for vancomycin because it has less toxicity on the
It has a hydrophilic head and a hydrophobic tail. Many molecules integrate into the cell membrane and
form. Resistance is
and the mechanism of action is
The three tastes that trigger a response without molecules entering the taste cells are
This is because tastants bind to
on the cell surface membrane in a very specific way. Once bound, the receptor protein
which triggers a series of chemical reactions that lead to the release of a
For the other two tastes -
- ions bind to ion channels which assist ions in entering the taste cells.
When compounds in tea leaves are released by breaking down the cells, they undergo
When green pigments are oxidised, they turn
Studies have shown that adding milk to tea inhibits the
but some studies suggest that this effect may be
- generally involved in defence against UV radiation, pathogens or predators. They are responsible for
(the drying feeling in the mouth when drinking tea.)
The savoury taste comes from the many
in tea. Tea also contains chlorophylls and
너는 정확하게 대답했다.
당신이 잘못 대답했습니다.
너는 시간이 없어.
점수 또는 평점을 저장하려면 로그인하거나 등록해야합니다.
텍스트에 적합한 오디오 언어를 설정하십시오.
단어를 강조 표시하여 학습을 향상시킵니다.
로그인 할 필요없이 퀴즈, 코스 및 플래시 카드를 재생할 수 있습니다. 그러나 점수를 저장하고 퀴즈, 코스 및 플래시 카드를 만들려면 로그인해야합니다. 오디오를 재생하려면 전문 계정에 로그인해야합니다.
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귀하가 작성한 질문이나 답변에 대한 오디오가 생성됩니다.
많은 사람들이 그들이 배운 것을 듣고 더 잘 배웁니다. 외국어 학습을 위해 우리는 18 개 이상의 언어를 지원했습니다.
지원 언어로는 덴마크어, 네덜란드어, 영어, 프랑스어, 독일어, 아이슬란드 어, 이탈리아어, 일본어, 한국어, 노르웨이어, 폴란드어, 포르투갈어, 루마니아어, 러시아어, 스페인어, 스웨덴어, 터키어, 웨일스 어 등이 있습니다.
또한 단어를 소리내어 읽음으로써 자동 단어 단위 강조 기능을 지원합니다.
Apple App Store에서 볼 Topgrade 응용 프로그램을 선택하십시오.
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