B3 Flashcards
What is a tissue ?
A group of cells with similar structure and function working together .
What is an example of a tissue ?
Muscular tissue and glandular tissue
What is the function of muscular tissue ?
They contract to bring about movement
What is the function of glandular tissue ?
Contains secretory cells that can produce and release substances such as enzymes and hormones .
What is an organ ?
A collection of tissues
What is an example of an organ and what tissues does it contain ?
The stomach and it contains , muscular tissue , glandular tissue and epithelial tissue .
What is another example of an organ ?
The pancreas
What are the two most important functions of the pancreas ?
It makes hormones to control blood sugar , as well as some enzymes that digest food . It contains two very different types of tissue which produce the secretions .
What is an organ system ?
A group of organs
What is an organism ?
Made up of a number of multiceullar organisms working together .
What are the three main organ systems ?
Digestive system , circulatory system and gas exchange system .
What is the process of digestion ?
- Mouth
- Gullet
- Diaphragm
- Liver
- Stomach
- Pancreas
- Large intestine
- Small intestine
- Rectum
- Anus
What is the function of the mouth ?
Mechanical digestion takes place here . The teeth chew the food into smaller pieces , amylase enzymes in saliva start digesting starch into maltose
What is the function of the oesophagus ?
The tube that connects the mouth to the stomach
What is the function of the stomach ?
Food is mechanically digested-by churning actions while protease enzymes start to chemically digest proteins . Hydrochloric acid is present to kill bacteria and so enzymes can work properly .
What is the function of the small intestine ?
Food coming out of the stomach finishes being digested by enzymes produced here and also secreted from the pancreas. Ph of the small intestine is slightly alkaline .
What is the function of the large intestine ?
Water is absorbed from remaining material in the colon to produce faeces . Faeces is tored in the rectum and removed through the anus
What is the function of the pancreas ?
Produces all three types of digestive enzymes: amylase, protease and lipase. Secretes enzymes in alkaline fluid into the duodenum for digestion to raise ph of fluid coming out of the stomach
What is the function of the liver ?
Produces Bile to emulsify fats an example of mechanical digestion
Amino acids not used to make proteins broken down here .
What is the function of the gall bladder ?
Stores bile to release into duodenum required
What is metabolism ?
The sum of all the reactions happening in the body .
What is an enzyme ?
Enzymes are biological catalysts made from protein , they speed up chemical reactions in cells .
What are the three main compounds that make up the structure of a cell ?
Carbohydrates,lipids and proteins
What do carbohydrates provide us with ?
Provide us with the fuel that makes all of the other reactions of life possible
What are all carbohydrates made up of ?
They are all made up of units of sugars
What is the best known unit of sugar as a carbohydrate ?
Glucose
What are the small carbohydrates units referred to ?
Simple sugars
Complex carbohydrates such as starch and cellulose are made up of….
Long chains of simple sugar units bonded together
What are the main carbohydrate rich foods ?
Bread , potatoes rice and pasta
What will most of the carbohydrates be broken down to and what will this be used for ?
Broken down to glucose used in respiration to provide energy for metabolic reactions in your cells .
What are examples of lipids ?
Fats and oils
Why are lipids important ?
Because they are the most efficient energy store in your body and an important source of energy in your diet
What are lipids made up of ?
Made up of 3 molecules of fatty acids joined to a molecule of glycerol
What are proteins used for ?
Proteins are used for building up the cells and tissues of your body , as well as the basis of your enzymes
What is a proteins molecule made up of ?
Long chains of small units called amino acids
What are three functions of protein in your body ?
- Structural components of tissues such as muscles and tendons
- Hormones such as insulin
- Antibodies
What is the test for starch ? What colour does the solution turn if starch is present ?
Iodine test and it turns blue black if starch is present
What is the test for sugars ? What colour does the solution go if sugar is present ?
Benedict’s solution and it turns red if sugars are present
What is the test for protein ? What colour does the solution go if it is present ?
Buiret test and the solution turns purple if protein is present
What is the test for lipids ? What colour does the solution go if it is present ?
Ethanol test and it turns cloudy
What is an enzyme ?
A biological catalyst that speeds up the rate of reaction
What are enzymes in terms of molecules ?
Large protein molecules
What is vital for an enzyme to function
The shape of it
What is the active site ?
It is where the substrate binds with an enzyme and reacts in the active site when it combines
What is the simple method of how enzymes work
The lock and key theory
What are the 3 steps to the lock and key theory ?
- Substrate and enzyme bind together fitting into the active site
- Substrate splits into products that leave the active site
- The enzyme is ready to use again
Different enzymes catalyse specific types of metabolic reactions , what are they ?
. Building large molecules from lots of smaller ones
. Changing one molecule into another
. Breaking down large molecules into smaller ones
What are two main factors that affect the rate of enzyme action ?
Temperature and ph
What happens to enzymes as temperature increases ?
The rate of reaction increases .
What happens to the enzymes when the temperature is too much ?
They denature and shrivel up , the active site shape changes
What temperature do human enzymes work best at ?
37 degrees
Do different enzymes work best at different ph levels ?
Yes
What are the enzymes called that break down carbohydrates ?
Carbohydrase
What are the enzymes called that break down protiens ?
Protease enzymes
Where are protease enzymes produced ?
Stomach , pancreas and small intestine
What enzyme breaks down lipids ?
Lipase
Where are lipase made ?
Pancreas and small intestine
What carbohydrase breaks down starch ?
Amylase
What conditions do the protease enzyme work best in ?
Acidic conditions
What conditions do the proteases need in order to function properly ?
Alkaline conditions
What is pepsin ?
A protease enzyme
What does the stomach produce in order for a protease enzyme like pepsin to work the best way ?
Hydrochloric acid
What protects the stomach walls from hydrochloric acid and enzymes ?
A thick layer of mucus made by the stomach
In the small intestine what conditions do the enzymes work best at ?
Alkaline conditions
How does the acidic liquid coming from your stomach become alkaline ?
The liver produces something called bile which is stored in the gall bladder
What does bile do ?
Neutralises the acid
What does bile also do ?
Emulsifies fats and breaks up fats into smaller droplets
