Untitled Deck Flashcards
What is the purpose of respiration?
To release energy
What are the reactants of aerobic respiration?
Glucose and oxygen
What are the products of aerobic respiration?
Carbon dioxide and water
What are the reactants of anaerobic respiration?
Glucose
What are the products of anaerobic respiration?
Lactic acid
What is the effect of excess lactic acid?
Cramp/muscle fatigue
Where in the cell does anaerobic respiration occur?
Cytoplasm
Where in the cell does aerobic respiration occur?
Mitochondria
Which type of respiration is more efficient?
Aerobic
When are you more likely to carry out anaerobic respiration>
During exercise
What is an oxygen debt?
The amount of oxygen required after exercising to break down lactic acid
Where in the lungs does gas exchange occur?
Alveoli
How do gases move in and out of the blood?
Diffusion
Why do exchange surfaces have large surface areas?
To speed up absorption (by diffusion or active transport)
Why do exchange surfaces have thin walls?
To reduce the distance of the diffusion pathway
Why do exchange surface have a good blood supply?
To maintain high concentration gradients to speed up diffusion
What gives the small intestine a large surface area?
Villi
What is the function of the heart?
Pumps blood around the body
What are the top two chambers of the heart called?
Right and left atrium
What are the two bottom chambers of the heart called?
Right and left ventricle
What is the function of the arteries?
To carry blood away from the heart
What is the function of the veins?
To carry blood towards the heart
What is the function of the capillaries?
Gas exchange within muscles and organs
How are the arteries adapted to carry blood at high pressure?
Elastic walls which recoil and return to their original shape
How are the veins adapted to carry blood at low pressure?
Valves to prevent backflow of blood
What is the purpose of valves?
To prevent the backflow of blood
How are capillaries adapted for gas exchange?
Thin walls - one cell thick
What are the four components of blood?
Red blood cells, white blood cells, platelets, plasma
What are the three types of blood vessels?
Arteries, veins and capillaries
What is the function of the red blood cells?
Carry oxygen
What do red blood cells contain which binds to the oxygen?
Haemoglobin
What is the function of the white blood cells?
They are part of the immune system
What is the function of platelets?
Help the blood to clot and form scabs
What is the function of plasma?
The liquid part of the blood which allows blood to flow
How are red blood cells different to any other animal cell?
They do not contain a nucleus
What is the function of the aorta?
Carries oxygenated blood away from the heart to the rest of the body
What is the function of the vena cava?
Carries deoxygenated blood from the body to the heart
What is the function of the pulmonary artery?
Carries deoxygenated blood from the heart to the lungs
What is the function of the pulmonary vein?
Carries oxygenated blood from the lungs to the heart
Which side of the heart contains oxygenated blood?
Left
Which side of the heart contains deoxygenated blood?
Right
Why are the walls of the left ventricle thicker than the right?
The left ventricle pumps blood around the whole body so needs to build up higher pressure
Name two substances carried by plasma (not blood cells or platelets)
Glucose, carbon dioxide, urea, salts, hormones, amino acids, fatty acids
Name three parts of the body where digestion occurs
Mouth, stomach, small intestine
Define digestion
Large, insoluble molecules are broken down into small, soluble molecules
What biological catalysts speed up digestion?
Enzymes
Name the enzyme which digests starch
Amylase
Name the products of starch digestion
Simple sugars/ glucose
What enzyme digests protein?
Protease or pepsin
What are the products of protein digestion?
Amino acids
Name the enzyme which digests lipids (fats)
Lipase
Name the products of lipid digestion
Fatty acids and glycerol
What enzyme does saliva contain?
Amylase
Give two examples of mechanical digestion
Teeth/chewing and stomach churning
Name the acid produced by the stomach
Hydrochloric
State two reasons why the stomach produces acid
- To kill pathogens/bacteria on food and 2. To provide optimum conditions for pepsin to digest proteins
What are the two functions of bile?
To neutralise stomach acid and to emulsify lipids
Why do lipids need to be emulsified?
To increase their surface area and speed up digestion by lipase
Where are nutrients absorbed into the blood?
Small intestine
What organ produces the enzymes needed for digestion?
Pancreas
Where is water absorbed into the blood?
Large intestine
Where is bile stored before release?
Gall bladder
State the reagent used to test for starch
Iodine
State the reagent used to test for lipids
Ethanol
State the reagent used to test for sugar
Benedict’s
State the reagent used to test for protein
Biuret
Describe the positive result for the test for starch
Brown –> Blue/black
Describe the positive result for the test for lipids
Clear –> Cloudy
Describe the positive result for the test for sugar
Blue –> Orange/red
Describe the positive result for the test for protein
Pale blue –> Lilac
What must be done when testing for sugar?
Heat sample and Benedict’s to at least 85 degrees
What is a stimulus?
A change in the environment
What is a receptor?
Something which detects a change
Give an example of a receptor
Sense organs, e.g. eyes, ears
What are the three types of neurone?
Sensory, motor, relay
Which neurone carries impulses from the receptor to the CNS?
Sensory
Which neurone carries impulses from the CNS to the effector?
Motor
Which neurone carries impulses within the CNS?
Relay
What is a synapse?
A gap between two neurones
How are nerve impulses transmitted across a synapse?
Chemical neurotransmitters diffuse across
What is an effector?
A muscle or gland which carries out a repsonse
What are the two parts of the central nervous system (CNS)?
Brain and spinal cord
What is a reflex action?
An involuntary, rapid response which does not pass through the brain
What is the purpose of a reflex action?
To prevent/reduce harm
Define what a gland is
An organ which produces hormones
Define what a target organ is
An organ which a hormone acts on
What is a hormone?
A chemical messenger carried in the blood
Name the hormone produced by the adrenal glands
Adrenaline
The “fight or flight” response ic caused by which hormone?
Adrenaline
Name the hormone produced by the thyroid
Thyroxine
Which hormone regulates your metabolism?
Thyroxine
What is the endocrine system?
The glands and hormones which regulate our internal environment
What is an organ?
different tissues working together to perform a specific job
What are the three different types of blood vessel?
arteries, veins and capillaries.
What are the three main types of digestive enzymes?
protease, lipase and carbohydrase.
What is the difference between receptors and effectors
Receptors are cells which detect stimuli, whereas effectors produce responses to stimuli.
What are the chemical messengers produced by glands of the endocrine system ?
Hormones