Energy for Life - Animals Flashcards
Respiration, Inhalation, Digestion, Circulatory System
What is cell respiration?
Cell respiration is the process of breaking down food molecules to release ATP
Word equation for aerobic respiration
Glucose + Oxygen —> Carbon Dioxide + Water
Symbol equation for aerobic respiration
C6H12O6 + 6O2 –> 6CO2 + 6H2O
What happens during anaerobic respiration?
Glucose is not completely broken down so less ATP is released. It also produce toxic waste products.
What is anaerobic respiration?
When cells respire without using oxygen.
Anaerobic respiration in animals equation
glucose —> lactic acid
How does we stop lactic acid building up
By oxidising it
What components make up the lungs?
- Trachea
- Bronchi
- Bronchiole
- Ribs
- Intercostal muscles
- Diaphragm
- Pleural membrane
- Alveoli
What happens during inhalation?
- Diaphragm contracts - moving down and flattening
- Rib cage moves up and outand the intercostal muscles contract.
- This causes the volume of the thorax to increase and air pressure in the thorax to decrease
- Air pressure in the thorax is less than atmospheric pressure causing air to move into the lungs
What happens during exhalation?
- Diaphragm relaxes - moving up and doming
- Intercostal muscles relax and rib cage moves down and in
- This cause the volume of the thorax to decrease and air pressure in the thorax
- Air pressure in the thorax is now more than atmospheric pressure, causing air to move out of the
lungs. to rise.
How are alveoli adapted for gas exchange?
- Large surface area
increases the rate of diffusion. - Each alveolus is surrounded by a network of capillaries this maintains a high concentration gradient and so speeds up diffusion.
- The walls of the alveoli are only one cell thick for a short diffusion distance.
Why does breathing rate increase during exercise?
We increase breathing rate during exercise as a response to increased levels of CO2 in the blood.
What are the harmful effects of smoking?
- Tobacco smoke contains carbon monoxide which permanetly binds to haemoglobin reducing the amount of oxygen that is transported by the blood.
- Tobacco smoke destroys cilia so musuc cannot be removed as easily.
- Smoke can damage alveoli so less oxgen gets to the blood this can cause an emphysema.
What is the function of iron?
Forms part of the haemoglobin which binds to oxygen
Deficiency disease of iron
anemia
Function of calcium in the body?
To form bones and teeth
Deficiency disease of calcium
rickets
Vitamin A function in the body?
Making a chemical in the retina and protecting the surface of the eye
Deficiency of Vitamin A causes…
Night blindness and damaged cornea
Vitamin C function in the body?
Needed for cells and tissues to stick together
Deficiency of Vitamin C causes…
Scurvy
Vitamin D function in the body?
Needed to absorb calcium and phosphate ions from food.
Deficiency of Vitamin D causes…
Rickets
Why do we need to eat fibre?
Fibre helps to movement of food through the intestine.
Ingestion definition
Taking food in through the mouth and swallowing
Digestion definition
Breaking down large insoluble molecules in food into smaller soluble molecules
Investigating the energy content of food practical method.
- Measure 25cm3 of water, pour it into the boiling tube
- Record the starting temperature.
- Light the foodstuff over a Bunsen, then hold the food under a boiling tube of water to heat it.
- If the food stops burning, it needs to be relit until it will no longer burn.
- Measure the finishing temperature of the
water and calculate the temperature change. - Use the following equation to determine energy:
Energy released (J) = mass of water (g) x rise in temperature (°C) x 4.2
Absorption definition
Movement of small soluble molecules out of the gut and into the blood by diffusion and active transport
Egestion definition
Passion out undigested food through the anus
Assimilation definition
Building larger biological molecules from the small soluble molecules in all cells
Describe how mechanical digestion occurs in the mouth
Food is broken up into smaller pieces in the mouth by chewing.
Describe how chemical digestion occurs in the mouth
Saliva is released into the mouth by the salivary glands. The saliva contains the enzyme amylase which breaks starch down into maltose.
How do we swallow?
The food is shaped into a ball (bolus) by the tongue and moved towards the back of the mouth. Food is then pushed down the oesophagus by peristalsis.
What is peristalsis?
Two sets of muscles push the food down the oesophagus. The circular muscles contract behind the bolus pushing it along. When the longitudinal muscles contract they make the oesophagus wider.
What is the epiglottis?
it is a flap that blocks the food from entering the trachea.
What is the oesophagus?
The oesophagus is a long tube that connects the mouth to the stomach.
What enzyme is produced in the stomach?
pepsin
What is the role of pepsin in the stomach?
It begins the process of digesting proteins into peptides
Why does the stomach contract?
To maximise contact between enzymes and food.
Why is hydrochloric acid released in the stomach?
Because pepsin works best in acidic conditions.
It also kills many bacteria and fungi which may be present in the food we eat.
What is the duodenum?
The first part of the small intestine.
What is the role of trypsin in the duodenum?
To break down proteins into peptides.
What is the role of amylase in the duodenum?
To break down starch into maltose
What is the role of lipase in the duodenum?
To break down lipids into fatty acids and glycerol.
What happens in the duodenum?
It is the site of chemical digestion
What is the role of maltase in the duodenum?
To break down maltose into glucose
What is the role of peptidase in the duodenum?
To break down peptides into amino acids.
Where is bile produced?
Liver
What is the role of bile in the duodenum?
1) Neutralises the stomach acid. Enzymes in the duodenum work best at pH 7-8.
2) Emulsifies lipids - breaks large droplets into smaller droplets, increasing the surface area for lipase to digest the fats
What is the ileum?
The second part of the small intestine
What happens in the ileum?
Small molecules are absorbed by diffusion. Some such as glucose are also absorbed via active transport.
How is the rate of diffusion increased in the ileum?
Large surface area - folding of ileum, villi and microvilli (folds on the surface of cells lining the villi) all increase surface area.
Short diffusion distance - the villi walls are one cell thick
High concentration gradient provided by capillary network and lacteals removing absorbed molecules.
What are the two parts of the large intestine?
The colon and the rectum
What happens in the large intestine?
The colon is the site for all reabsorption of water. The faeces are then stored in the rectum and egested from the anus.
Where does the pulmonary artery carry blood?
to the lungs FROM the heart.
Where does the pulmonary vein carry blood?
from the lungs TO the heart
Where does the vena cava carry blood?
from the body TO the heart.
Where does the aorta carry blood?
to the body FROM the heart
Where does the hepatic artery carry blood?
from the heart TO the liver
Where does the mesenteric artery carry blood?
from the heart TO gut
Where does the renal artery carry blood?
from the heart TO the kidneys
Where does the hepatic vein carry blood?
from the liver TO the heart
Where does the hepatic portal vein carry blood?
from the gut TO the liver
Where does the renal vein carry blood?
from the kidneys TO the heart
What type of circulatory system do human have?
A double circulatory system
What are the four chambers in the heart?
- Right atrium
- Left atrium
- Right ventricle
- Left ventricle
Which ventricle wall is thicker?
Left
Why is the left ventricle wall thicker?
So it can pump blood at higher pressures so that the blood can travel around the whole body.
What valve is in-between the right atrium and right ventricle?
Tricuspid valve
What valve is in-between the left atrium and left ventricle?
Bicuspid
What valve is in-between the right ventricle and pulmonary artery?
Semi-lunar valve
What valve is in-between the left ventricle and aorta?
Semi-lunar valve
What happens to the heart when we exercise?
1) When we exercise muscles produce more CO2 in aerobic respiration.
2) Sensors in the aorta and carotid artery detect this increase
3) They send nerve impulses to the medulla
4) The medulla responds by sending nerve impulses along the accelerator nerve
5) The accelerator nerve increases the heart rate
Why do we need a higher heart rate when we exercise?
To meet the demands of increased aerobic respiration.
What is the role of plasma?
Transports blood cells and many other substances, including:
glucose, amino acids, urea, carbon dioxide, hormones, proteins and heat energy.
What is the role of RBCs?
Transports oxygen, bound to haemoglobin.
What is the role of platelets?
Release chemicals when the blood is exposed to air.
Causing soluble fibrinogen to be converted to insoluble fibrin.
Fibrin forms a mesh, which traps platelets and red blood cells - this is a clot
What is the role of phagocytes?
To engulf and digest pathogens
What is the role of lymphocytes?
To make and release antibodies, which bind to and destroy pathogens
How are red blood cells specialised for their job?
Red blood cells contain haemoglobin, which combines with oxygen to form - this transports oxygen to respiring cells
They have no nucleus, so more oxygen can be transported.
They are biconcave this increases their surface area: volume ratio. This increases the rate of diffusion.
Structure of an artery?
- thick outer wall
- thick elastic layer
- thick muscular layer
- small lumen
Structure of a vein?
- fairly thin outer wall
- thin elastic layer
- thin muscular layer
- has valves
Structure of a capillary?
- wall is one cell thick
- very small lumen
What factors increase the risk of having CHD
Diet - eating lots of saturated fat increases blood cholesterol and increases the risk of fatty deposits
Smoking - increases blood pressure and increases the risk of fatty deposits forming
High blood pressure - damages the artery lining and increases the risk of fatty deposits forming. High salt levels in your diet increase the risk of high blood pressure.
What is CHD?
When fatty deposits will build up in the artery walls. The fatty deposits narrow the lumen of the artery. This is a
problem in the coronary arteries as it restricts blood flow to the heart muscles cells.
This means the heart muscle cells receive less oxygen (and glucose) for aerobic respiration. So aerobic respiration reduces and anaerobic respiration increases in the heart muscle cells.
Lactic acid will build up due to the increase in anaerobic respiration, poisoning the heart muscle cells and causing heart attacks.
