6.1 Coordinated body systems Flashcards
What is metabolism and what two groups are they divided into?
Metabolism – Chemical reactions are known as metabolism. Metabolism is the chemical process that maintains life and allow organisms to grow, reproduce maintain their structure and respond to their environments.
Chemical reactions of metabolism are divided into two groups:
* Anabolic - Reactions that break down organic matter – e.g. respiration which breaks down the glucose molecule to release energy.
* Catabolic - Reactions that build complex molecules from simpler substances – e.g. the construction of new cells and cell components
What are Enzymes?
Enzymes – chemicals that speed up the rate of a reaction without being used in the process. There are over 700 enzymes in the body. Each enzyme has a particular shape that allows it to attach to a specific molecule or molecules known as the substrate. The substrate is what will be changed by the chemical reaction. In a reaction the enzyme and the substrate join together, and the substrate is changed in some way.
What are Carbohydrates, proteins and lipids broken down into?
- Carbohydrates are broken down into glucose in chemical reactions
- Proteins are broken down into amino acids in chemical reactions
- Lipids (fats and oils) are broken down into fatty acids and glycerol
What is diffusion
Diffusion - is the movement of particles from an area where there is a lot of that type of particle (high concentration) to an area where there is not much of that particle (low concentration). Diffusion takes place in liquids and gases. E.G. After eating there are high concentrations of glucose, amino acids, and diffusion carries them into villi, through the capillaries and evenly spreads them through your body via blood vessels.
How does oxygen get diffused through your body?
The air you breathe enters your respiratory system through your nose, then it passes through the trachea, bronchi, bronchioles and ends up in the alveoli. Walls of the alveoli are only one cell thick and are surrounded by capillaries. Oxygen in the alveoli diffuse into capillaries into blood. Blood gets diffused through the body.
What is the circulatory system and what does it do?
Circulatory system – consists of arteries, capillaries, veins which carry materials to every cell in your body. The heart pumps which move the blood around the body. Without blood moving cells will be starved of the materials they need to function.
What two parts of the heart cause the heartbeat rhythm? What is ventricular fibrillation?
The heart is made of cardiac muscle. Cardiac muscle naturally contracts and relaxes without any input from the nervous system. The rhythm of the heartbeat is initiated by a small patch of muscle called a peacemaker ( or SA node). The rhythm of relaxation and contraction of the peacemaker sets the rhythm for the heart beat. The peacemaker stimulates both atrua to contract simultaneously. When the stimulus reaches the tissue between the atria and the ventricles another small patch of specialised tissue ( the AV mode) stimulates both ventricles to contract.
If the impulses in the ventricles become disorganised because the stimulus is not picked up correctly, the muscle of the ventricle begin to twitch spasmodically. This is a condition known as ventricular fibrillation. Blood flow stops and unless the heart rhythm is restored death will follow swiftly. A defibrillator is used to give the heart a jolt with electricity current, in a attempt to restore the hearts natural rhythm and save the person’s life.
How does a cross country race affect the heart rate? What are receptors?
- Cellular respiration increases as does the carbon dioxide (CO2) level in the blood. Receptors are specialized cells that detect stimuli changes in the carotid artery ( in your neck) and the aorta ( the artery leading from your heart) detect the increased CO2 concentration and sends messages to your brain which makes your nerves stimulate your heart to beat faster.
- As muscular activity increases more blood is pumped to the right atrium. The atrium wall stretches to hold extra blood. Stretch receptors in the wall of the atrium send nerve impulses to the brain, which makes the heartbeat faster.
What does the organelle mitochondria do?
Mitochondria - are the organelles in which cellular respiration takes place. Oxygen and glucose enter the cell from the blood capillaries and move through the cytoplasm to the mitochondria where they are used in cellular respiration. Cellular respiration is a series of chemical reactions assisted by enzymes which release energy from glucose.
What does the organelle Ribosomes do?
Ribosomes – at the ribosomes, amino acids from the proteins you have are digested are reassembled into proteins your body can use. Enzymes and hormones are proteins as are parts of cell membranes in muscle fibers.
What does the organelle Lysosomes do?
Lysosomes – are organelles that treat waste within cells. Lysosomes digest dying cells, damaged organelles and viruses or bacteria that have invaded a cell. The products of lysosome digestion move from the cell to the bloodstream.
What does the liver do?
Liver – Largest organ in the body. The liver:
* Break down hormones
* Breaks down hemoglobin (from dead red blood cells) creating products that are added to bile and then disposed of through digestive system.
* Breads down or modifies toxic substances and most medicines – an excess of toxins such as alcohol may cause permanent damage to the liver
* Converts ammonia to urea
