Oxygen
Sugar
Bacteria
Carbon dioxide
Yeast in Food Production
- Microorganisms can be used by humans to produce foods and other useful substances.
- One example of this is the production of bread using yeast.
- Yeast is a single-celled fungus that can carry out both aerobic and anaerobic respiration.
Making bread : During bread making yeast is added to bread dough. The yeast produces enzymes that break down the starch in flour, releasing sugars that can be used by the yeast in respiration. The yeast begin to respire aerobically but will switch to anaerobic respiration when oxygen runs out. When yeast carries out anaerobic respiration it produces alcohol (ethanol) and carbon dioxide. The carbon dioxide produced by the yeast is trapped in small air-pockets in the dough, causing the dough to rise (increase in volume). The dough is then baked in a hot oven to form bread. During baking any ethanol produced by the yeast is evaporated in the heat, so bread doesn’t contain any alcohol. The yeast is killed by the high temperatures used during baking. This ensures there is no further respiration by the yeast.
If you are interested in preparing for the CSS MPT and other FPSC, SPSC, and PPSC General Recruitment Tests with us, get in touch with us.
Related MCQs
- On which date cabinet Mission arrived in Delhi? (CSS 2022 Pakistan Affairs Paper)
- 24 March 1945
- 24 March 1946
- 24 March 1947
- None of these
Submitted by: CSS Exam Desk Team
- What is Anthracite? (CSS 2019 General Science & Ability Paper)
- Carbon
- Pure Carbon
- Ammonia
- None of these
Submitted by: CSS Exam Desk Team
- The SYNONYM of the word \"NUMMARY\" is? (CSS 2017 English Precis & Composition Paper)
- Of coins
- Fabricate
- Working Capital
- Fastidiousness
Submitted by: CSS Exam Desk Team
- Who is Nicolas Sarkozy? (CSS 2009 Current Affairs Paper)
- German Chancellor
- Canadian President
- French President
- President of Georgia
Submitted by: CSS Exam Desk Team
- The SYNONYM of the word \"LACUNAE\" is? (CSS 2007 English Precis & Composition Paper)
- Shallow water
- Local dialect
- Missing parts
- Tiny marine life
Submitted by: CSS Exam Desk Team
- Warsak Dam is located in? (PPSC PMS Punjab General Knowledge Paper, December 15, 2024)
- Sindh
- Punjab
- Balouchistan
- Khyber Pakhtunkhwa
Submitted by: CSS Exam Desk Team
- according to Nabi Akram ( (صلی اللہ علیہ وسلم) the most favourite place of allah is? (CSS 2012 Islamic Studies Paper)
- eidgah
- bazar
- mosque
- home
Submitted by: CSS Exam Desk Team
- Serial pin has how many minimum ports? (CSS 2015 General Science & Ability Paper)
- 7
- 9
- 11
- None of these
Submitted by: CSS Exam Desk Team
- In fish liver oil there is? (CSS 2023 General Science & Ability Paper)
- Vitamin A only
- Vitamin D only
- Vitamin A and vitamin E
- Vitamin A and Vitamin D
Submitted by: CSS Exam Desk Team
- The day and night are formed due to \'Earth\' rotation on its own axis from? (CSS 2023 Special General Science & Ability Paper)
- North to South
- South to North
- East to West
- West to East
Submitted by: CSS Exam Desk Team
- Who was formal teacher of Syed Ahmed Barelvi? (CSS 2011 Pakistan Affairs Paper)
- Sheikh Ahmed Sirhandi
- Shah Walliullah
- Shah Abdul Aziz
- None of these
Submitted by: CSS Exam Desk Team
- Who was elected as the Prime Minister of Pakistan after the 2002 general elections? (PPSC Tehsildar General Knowledge Test, December 15, 2024)
- Chaudhry Shujaat Hussain
- Mian Muhammad Azhar
- Mir Zafarullah Jamali
- Chaudhry Parvez Elahi
Submitted by: CSS Exam Desk Team
- Who Suggested Treatment Of Chicken Pox? (CSS 2018 Islamic Studies Paper)
- Al-Zahrawai
- Ibn-Sina
- lbn-Zakriya
- lbn-Zakriya
Submitted by: CSS Exam Desk Team
- Who Was The Head Of Tadwwen Quran (Compilation Of Quran) Committe? (CSS 2018 Islamic Studies Paper)
- Hazrat Abdul Rahman Bin Auf(رضی اللّٰہ عنہ)
- Hazrat Abdullah Bin Saad(رضی اللّٰہ عنہ)
- Hazrat Zaid Bin Sabit(رضی اللّٰہ عنہ)
- None of these
Submitted by: CSS Exam Desk Team
- A moderator is used in nuclear reactor in order to: (CSS 2009 General Science & Ability Paper)
- Accelerate the neutrons
- Slow down the speed of the neutrons
- Increase the number of electrons
- Decrease the number of electrons
Submitted by: CSS Exam Desk Team
- Martin Luther King Jr was assassinated in the age of? (CSS 2015 Current Affairs Paper)
- 33
- 37
- 39
- None of these
Submitted by: CSS Exam Desk Team
- The solid and liquid can be separated by the Process of? (CSS 2015 General Science & Ability Paper)
- Distillation
- Magnetism
- Filtration
- None of these
Submitted by: CSS Exam Desk Team
- Arthur C. Clark. the famous science fiction author. while working as a radio operator in the World War-l? (CSS 2012 General Science & Ability Paper)
- Proposed that a network of satellite in stationary orbit at very high altitudes around the earth be used to bounce communication Signals all over the world
- Postulated the existence of extraterrestrial artifacts on the moon
- Proposed building a space elevator from carbon carbon monofilaments
- None of these provided options
Submitted by: CSS Exam Desk Team
- Carbohydrate content in potato (per 100g) is? (CSS 2016 General Science & Ability Paper)
- 18g
- 13g
- 25g
- 26g
Submitted by: CSS Exam Desk Team
- The use of antibiotic is a very effective way of killing disease causing bacteria. Sometime people don’t finish all of their pills. This can result in? (CSS 2014 General Science & Ability Paper)
- Some bacteria left unkilled
- Production of more bacteria
- Bacteria becoming sensitive to antibiotics
- Bacteria becoming resistant to antibiotics
Submitted by: CSS Exam Desk Team
- the method of ablution is in surah? (CSS 2012 Islamic Studies Paper)
- al-baqrah
- al-maidah
- al-noor
- al-nisaa
Submitted by: CSS Exam Desk Team
- Nursi’s Movement ls A Religious Movement In? (CSS 2018 Islamic Studies Paper)
- Syria
- Turkey
- Egypt
- Albania
Submitted by: CSS Exam Desk Team
- Indicate the name of prophet on whom the Holy Book Zaboor was revealed? (CSS 2019 Islamic Studies Paper)
- Hazrat lbrahim(علیہ السّلام)
- Hazrat Musa (علیہ السّلام)
- Hazrat Esa (علیہ السّلام)
- Hazrat Dawood (علیہ السّلام)
Submitted by: CSS Exam Desk Team
- The shape of the external ear is due to? (CSS 2013 General Science & Ability Paper)
- Elastic cartilage
- Fibrocartilage
- Fibrocartilage
- None of these
Submitted by: CSS Exam Desk Team
- If an alkali is slowly added to an acidic solution, the pH of the acidic solution will? (CSS 2011 General Science & Ability Paper)
- Increase
- Decrease
- Increase to 7 and then decrease
- Decrease to 7 and then increase
Submitted by: CSS Exam Desk Team