Life Flashcards
Processes
What is the word equation for aerobic respiration?
Glucose + Oxygen → Carbon Dioxide + Water + Energy
From which system does the body obtain glucose for respiration?
The digestive system
In which part of our cells does respiration mainly occur?
in the mitochondria.
What are the products of respiration?
carbon dioxide and water.
How do we test for carbon dioxide?
limewater, turns cloudy
The word ‘aerobic’ indicates the presence of which gas?
oxygen.
Which unit is energy measured in
joules, J
Symbol for kilojoule
kJ (lower case k, uper case J)
If food is high in energy, what nutrient is it likely to contain
fats/lipids, carbohydrates
7 nutrients needed by the body
Lipids/fats, carbohydrates, vitamins, fibre, water, protein, minerals
What nutrient repairs muscles
Protein
Why do we need fibre?
Add bulk to food to help it pass through the digestive system; prevents constipation
Scurvy happens when?
Vitamin
C deficiency
2 soutces of vitamin C
Fruits and vegetables
Rice, potatoes and bread are sources of
Carbohydrates
Meat, fish, nuts are good sources of
Protein
Sugar and starch are types of
Carbohydrates
Test to detect starch is?
Iodine
When testing for starch what colour change shows a positive result
Brown or black
Test to detect sugar
Benedicts
When testing for sugar what colour change shows a positive result
Blue or red
Test to detect protein
Bieuret
When testing for protein what colour change shows a positive result
Blue of purple
Test to detects fats
Ethanol
When testing for fats what change shows a positive result
Cloudy emulsion formed
What is digestion
The process of breaking down food into substances our body can absorb and use
Where does mechanical digestion mainly occur?
The Mouth
List the organs the food will travel through on its way through the digestive system
Mouth, oesophogus, stomach, small intestine, large intestine, rectum, anus
Which nutrient starts to be chemically digested in the mouth?
Carbohydrate
Where does digestion of protein take place?
Stomach, Small Intestine
Where does digestion of lipids take place?
Small Intestine
Which organ produces carbohydrase, protease and lipase?
Pancreas
What is the purpose of hydrochloric acid in the stomach?
Provides the right pH for the protease enzymes; kills bacteria
What is the purpose of bile in the digestive system?
Neutralise the acid which was added to food in the stomach to give the best pH for enzymes to work. Break down (emulsify) fat
Where is bile produced?
Liver
Where is bile stored?
Gall Bladder
The site of maximum absorption in the digestive system is…
Small Intestine
During digestion, carbohydrate is broken down into
Glucose
During digestion, protein is broken down into
Amino Acid
During digestion, lipids are broken down into
Fatty Acid and Glycerol
Which enzyme digest protein?
Protease
Which enzyme digests carbohydrates?
Carbohydrase
Which enzyme digests fats?
Lipase
Why is fibre not digested into the body?
People don’t have the right enzymes to digest them
Why are vitamins and minerals not digested in the body?
They are absorbed
What is the purpose of bacteria in our gut?
Digest food we cannot (e.g. cellulose) to give us essential nutrients (e.g. vitamin K)
In which part of the digestive system does water and mineral absorption take place
Large Intestine
How is the small intestine adapted to increase the rate of absorption?
Villi and microvilli to increase surface area; a good blood supply to transport nutrients; mucus for lubrication; glucose moves from a high concentration in the intestine to a lower concentration in the blood.
What are the optimum conditions for amylase?
Neutral pH, 37 degreesC
What happens to an enzyme if it is boiled or exposed to a strong acid?
It is denatured
What is the scientific name for the windpipe?
Trachea
The trachea divides into two ________. These then divide into __________
Bronchi, Bronchioles
What are the air sacs at the end of each bronchiole called?
Alveoli
Breathing in and out is also known as…
Ventilation
When we inhale, the volume inside the thorax ____________ so the pressure inside the thorax _____________
Increases, Decreases
When we exhale, the diaphragm relaxes and moves upward/downward?
Upward
What features do alveoli have to maximise gas exchange?
Large surface area; concentration gradient (oxygen and carbon dioxide can diffuse); good blood supply; capillary wall only 1 cell thick
Write the word equation for anaerobic respiration in cells
glucose -> lactic acid
What is anaerobic respiration in yeast cells known as?
Fermentation
Which releases more energy - aerobic or anaerobic respiration?
aeorbic
Give an example of where fermentation is used
brewing or baking
Products of fermentation
Ethanol Carbon Dioxide
