8. Metabolism requirements Flashcards
What is the chemical reactions that occur to support life?
Metabolism.
Right now in every one of your cells, a huge number of chemical reactions are taking place to keep you alive.
Metabolic reactions are grouped based on whether they build up molecules into bigger ones or break down molecules into smaller ones. What are they called?
Anabolism or catabolism.
Cells need many chemicals so they can undergo metabolism.
They may need to break down large molecules to release energy or to make molecules small enough to transport.
These are what reactions?
Catabolic.
Cells may need to build small molecules up into larger molecules for storage or to build components of the cell.
These are what reactions?
Anabolic.
Cells require oxygen for what?
Aerobic respiration.
This is a series of chemical reactions which help release the energy from food molecules and occurs where?
In the mitochondria.
Without oxygen, human cells have to switch to anaerobic respiration, which produces much less energy and the waste product of what?
Lactic acid
The body can only survive using anaerobic respiration for a very short time. Without oxygen the body will die..
Oxygen is a small molecule, so can enter the cells across the cell membrane by what method?
Diffusion.
Oxygen is carried around the body attached to what in the red blood cells?
Haemoglobin.
With capillaries throughout the tissues, this allows rapid delivery of oxygen to every cell in the body.
Cells also require many nutrients, including what?
Carbohydrates, proteins, lipids, vitamins and minerals.
Carbohydrates, proteins, and fats that we eat are complex molecules, and cannot be used by our cells directly.
Complex foods are broken down into simple forms bywhat?
The digestive system.
Look at the name carbohydrate. The name tells you which atoms it contains. Carbo- means it contains carbon and -hydrate tells you it contains what?
Hydrogen and oxygen.
Carbohydrate = carbon + hydrogen + oxygen
Carbohydrates are classified based on their size.
Simple carbohydrates are small sugar molecules. They can be what?
Monosaccharides such as glucose or disaccharides such as maltose, which is made of two glucose molecules joined together.
Complex carbohydrates are large molecules, otherwise known as polysaccharides. They include what?
Molecules such as starch, glycogen and cellulose, which is the component of plant cell walls we commonly call fibre.
We gain carbohydrates by eating foods rich in fibre, starch or sugar.
Starch is digested by enzymes (amylase) to form glucose, which can be absorbed with the other sugars through the small intestine into the blood. Fibre is not digested and remains where?
In the intestine.
The main role of carbohydrates in the body is what?
To supply energy.
Sugar is taken into cells where it is broken down by aerobic respiration to release energy in the form of what?
ATP (adenosine triphosphate).
Sugars also play an important role in cell signalling and recognition, with sugar groups added to proteins to form what?
Glycoproteins.
What plays an important role in maintaining the health of the gut, as it adds bulk to the food which helps scrape the walls clean as it passes through by peristalsis?
The cellulose (fibre).
What is cellulose also known as?
Fibre.
What are some examples of foods containing simple and complex carbohydrates?
Proteins are polymers of what?
Amino acids.
Amino acids contain the elements carbon, hydrogen, oxygen and nitrogen, and sometimes sulphur.
Foods rich in proteins include what?
Meats, fish, nuts, legumes and dairy.
The proteins have to be digested by enzymes called what into amino acids, so they are small enough to be absorbed into the body?
Proteases.
