化学のみ：酵母による発酵により水溶液状のエタノールが生じる
導入済み| English | 意味 |
|---|---|
| anaerobic conditions/ˌæneəˈrəʊbɪk kənˈdɪʃnz/ | 無氧条件 |
| fermentation/fɜːmənˈteɪʃn/ | 発酵 |
What would explain this observation?
- Bubbles from a yeast/sugar mixture are evidence of gas production. They do not directly measure ethanol concentration or show that every molecule of sugar has fermented.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Yeast enzymes convert sugars in aqueous solution into ethanol and carbon dioxide in anaerobic conditions 无氧条件. A warm temperature, commonly around 30–40 °C in teaching examples, supports fermentation 发酵; low temperature slows activity and excessive heat damages the enzymes or kills yeast. Oxygen is excluded from the fermentation mixture while carbon dioxide can escape through an approved arrangement. The result is an aqueous solution of ethanol, not pure ethanol.
- fermentation: Anaerobic conversion of sugars by yeast to an aqueous ethanol solution and carbon dioxide; anaerobic conditions: Conditions excluding oxygen from the stated biological process.
教授されたエタノール発酵を支持する条件はどれか？
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
発酵は糖溶液に対して酵母酵素を用い、暖かい（熱くはない）条件下で行うが、酸素は排除する。酸素がある場合、酵母は好気呼吸を行う。300 ℃では酵母が死滅し、ニッケルは水素化に関与する。
各専門用語を正確な意味と対応させよ。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
関連する物理量やプロセスを区別するために定義を使用せよ。
Choose evidence that can test it
- Maintain the school-selected temperature and sugar concentration, use the prepared yeast and record actual gas or mass observations over time. An airlock can let gas leave without freely admitting outside air; it is not a licence to tightly seal a gas-producing bottle. The rate can change as substrate runs low or ethanol inhibits yeast. Gas bubbling is qualitative unless quantity is measured, and a silent vessel is not by itself proof that no ethanol is present.
- For an actual supervised activity, compare matched labelled mixtures with a yeast-free control and the same volumes, sugar concentration and temperature. Retain raw observations and repeat comparisons. Analyse differences cautiously because gas leakage, dissolved carbon dioxide and contamination affect measurements. Any later separation of ethanol requires approved equipment and no flame near flammable vapour. Products of school fermentation must not be consumed.
この場合、調査やモデルをより妥当にする2つの習慣は何か。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
条件や仮定を明記することで他者が正確に再現でき、根拠となる証拠を記録することで結論を検証できます。相反する結果を隠すと、誤った結論を疑う証拠を失いますし、単一の測定でより広い主張を成立させることはできません。
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: three illustrative gas readings over the same interval are 18, 21 and 21 cm³. Mean volume=(18+21+21)/3=20 cm³. A yeast-free control gives 2 cm³, so the difference is 18 cm³ under this measurement method. This does not directly determine ethanol volume without an appropriate relation and complete gas accounting. The route differs from adding steam to ethene with an acid catalyst.
Repeat gas volumes over one fixed interval are 24, 27 and 27 cm³. Find their mean. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
一定区間におけるガスの体積の繰り返し測定値が 24、27、27 cm³ である。その平均値を求めよ。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
結果は 26 cm³ である。既知：反復体積 24、27、27 cm^3。平均値 = 総和 ÷ 回数。総和 = 78。平均値 = 78/3 = 26 cm^3。記録された理由がない限り、反復測定を除外してはいけない。
Check the conclusion and its limits
- Do not replace yeast with nickel, use the industrial hydration temperature for living yeast or describe fermentation as requiring an oxygen supply. A mass loss can include escaping gas but needs its own controls. No balanced fermentation equation is required by this acquired alcohol section, and the task is preparation for authentic supervised work rather than a replacement written examination.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Fermentation produces pure ethanol without water. This claim is false: Fermentation produces ethanol IN WATER - the sugar solution remains the bulk of the mixture and must be distilled to concentrate the alcohol. Pure ethanol directly from fermentation is impossible.
Chemistry-only: yeast fermentation produces aqueous ethanol: Maintain the school-selected temperature and sugar concentration, use the prepared yeast and record actual gas or mass observations over time. An airlock can let gas leave without freely admitting outside air; it is not a licence to tightly seal a gas-producing bottle. The rate can change as substrate runs low or ethanol inhibits yeast. Gas bubbling is qualitative unless quantity is measured, and a silent vessel is not by itself proof that no ethanol is present.
発酵は水を含まない純粋なエタノールを生産する。
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
発酵によって生成されるエタノールは水溶液中に存在するため、糖溶液が混合物の大部分を占め、アルコールを濃縮するために蒸留が必要です。発酵のみから直接純粋なエタノールを得ることはできません。
酵母による糖の嫌気的変換で、エタノール水溶液と二酸化炭素が生じる場合、技術用語を記せ。
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
発酵とは、酵母による糖の嫌気的変換でエタノール水溶液と二酸化炭素が生じることを指す。