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=**Life Processes**=

There are 7 main life processes and they each have their own job to make the body function. Carbon is vital in making each of the processes work because carbon is vital for life. Without Carbon nothing would be alive. Also, Carbon starts out all of these processes through photosynthesis. Photosynthesis is when plants take in carbon dioxide and turn it into energy and let out oxygen. Therefor, carbon creates oxygen which we breathe in and that keeps us alive. Carbon is vital in the 7 life processes.
 * Introduction:**

Various functions are going inside our body and inside the body of all living organisms. These functions are necessary to maintain the living being. The maintenance functions of living organisms must go on even when they are not doing anything particular. Even when we are just sitting in front of computer, even if we are just asleep, this maintenance job has to go on. The processes which together perform this maintenance job are life processes.
 * Definiton:**

There are seven things that they need to do to count as being alive. The phrase ** MRS GREN ** is a way to remember them:
 * Important info:**
 * M || Movement || All living things move, even plants ||
 * R || Respiration || Getting energy from food ||
 * S || Sensitivity || Detecting changes in the surroundings ||
 * G || Growth || All living things grow ||
 * R || Reproduction || Making more living things of the same type ||
 * E || Excretion || Getting rid of waste ||
 * N || Nutrition || Taking in and using food ||

It can be easy to tell if something is living or not. A teddy bear might look like a bear, but it can't do any of the seven things it needs to be able to do to count as being alive.

What about a car? A car can move, it gets energy from petrol (like nutrition), it might have a car alarm (sensitivity), and it gets rid of waste gases through its exhaust pipe (excretion). But it can't grow or make baby cars. So a car is not alive.

**Respiration** Respiration is a chemical reaction that happens in all living cells. It is the way that energy is released from glucose, for our cells to use to keep us functioning. Remember that respiration is **not** the same as breathing (which is properly called ventilation). **Aerobic respiration** The glucose and oxygen react together in the cells to produce carbon dioxide and water. The reaction is called **aerobic respiration** because oxygen from the air is needed for it to work. Here is the word equation for aerobic respiration: **glucose + oxygen** **→** **carbon dioxide + water (+ energy)** **(Energy is released in the reaction. We show it in brackets in the equation because energy is not a substance.)** Now we will look at how glucose and oxygen get to the cells so that respiration can take place and how we get rid of the carbon dioxide. **Glucose from food to cells** Glucose is a type of **carbohydrate**, obtained through digestion of the food we eat. Digestion breaks food down into small molecules. These can be absorbed across the wall of the small intestine into the bloodstream. Glucose is carried round the body dissolved in blood plasma, the pale yellow liquid part of our blood. The dissolved glucose can diffuse into the cells of the body from the **capillaries**. Once in the cell glucose can be used in respiration. **Oxygen from the air to cells** When we breathe in oxygen enters the small air sacs, called **alveoli**, in the lungs. Oxygen diffuses from there into the bloodstream. Oxygen is not carried in the plasma, but is carried by the red blood cells. These contain a red substance called **hemoglobin**, which joins onto oxygen and carries it around the body in the blood, then lets it go when necessary. Like glucose, oxygen can diffuse into cells from the capillaries. Red blood cells carry oxygen around the body **Carbon dioxide from cells to the air** The carbon dioxide produced during respiration diffuses out of the cells and into the blood plasma. The blood carries it to the lungs. It then diffuses across the walls of the alveoli and into the air, ready to be exhaled.

**The respiratory system and ventilation**



**The respiratory system** The human respiratory system contains the organs that allow us to get the oxygen we need and to remove the waste carbon dioxide we don't need. It contains these parts: · lungs · tubes leading from the lungs to the mouth and nose · various structures in the chest that allow air to move in and out of the lungs. **Ventilation** Movements of the ribs, rib muscles and diaphragm allow air into and out of the lungs. Take care - this is called **breathing** or **ventilation**, not respiration. When we breathe in, we inhale. When we breathe out, we exhale. Air passes between the lungs and the outside of the body through the **windpipe**, called the **trachea**. The trachea divides into two bronchi, with one bronchus for each lung. Each bronchus divides further in the lungs into smaller tubes called bronchioles. At the end of each bronchiole, there is a group of tiny air sacs. These air sacs have bulges called **alveoli** to increase their surface area.

**Gas exchange**



We need to get oxygen from the air into the blood, and we need to remove waste carbon dioxide from the blood into the air. Moving gases like this is called gas exchange. The alveoli are adapted to make gas exchange in lungs happen easily and efficiently. Here are some features of the alveoli that allow this: The gases move by **diffusion** from where they have a high concentration to where they have a low concentration: · Oxygen diffuses from the air in the alveoli into the blood. · Carbon dioxide diffuses from the blood into the air in the alveoli. Some **water vapour** is also lost from the surface of the alveoli into the lungs - we can see this condensing when we breathe out on cold days.
 * they give the lungs a really big surface area
 *  they have moist, thin walls (just one cell thick)
 *  they have a lot of tiny blood vessels called capillaries.

**Movement** **Why do we need a skeleton?** Our skeleton is made of more than 200 bones. **Calcium** and other minerals make the bone strong but slightly flexible. Bone is a living **tissue** with a blood supply. It is constantly being dissolved and laid down, and it can repair itself if a bone is broken. Exercise and a balanced diet are important for a healthy skeleton. The skeleton has three main functions: **Support** The skeleton supports the body. For example, without a backbone we would not be able to stay upright. **Protection** Here are some examples of what the skeleton protects: · the skull protects the brain · the ribcage protects the heart and lungs · the backbone protects the spinal cord. **Movement** Some bones in the skeleton are joined rigidly together and cannot move against each other. Bones in the skull are joined like this. Other bones are joined to each other by **flexible joints**. Muscles are needed to move bones attached by joints.
 * to support the body
 * to protect some of the vital organs of the body
 * to help the body move.

**Joints** This page is about the joints in the skeleton that allow movement. **Basic structure** If two bones just moved against each other, they would eventually wear away. This can happen in people who have a disease called **arthritis**. To stop this happening, the ends of the bones in a joint are covered with a tough, smooth substance called **cartilage**. This is kept slippery by **synovial fluid**. Tough **ligaments** join the two bones in the joint and stop it falling apart. The diagram shows the main features of a joint. **Movement** Different types of joint allow different types of movement. · **Hinge joints** allow simple movement, the same as a door opening and closing. Knee and elbow joints are hinge joints. · **Ball and socket joints** allow movement in more directions. Hip and shoulder joints are ball and socket joints. The bones cannot move on their own - they need muscles for this to happen.

Works Cited : "Life Processes." //BBC News //. BBC, n.d. Web. 26 Apr. 2013. .

"Life Processes." //BBC News //. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/3/>.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"Life Processes." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">BBC News //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/4/>.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"Life Processes." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">BBC News //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/5/>.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"Life Processes." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">BBC News //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/6/>.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"Life Processes." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">BBC News //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/7/>.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"Life Processes." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">BBC News //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. BBC, n.d. Web. 26 Apr. 2013. <http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/life_processes/revision/8/>.