Organisation And The Digestive System Flashcards
What are tissues?
A group of cells with similar structure and function working together.
What are the three kinds of tissues?
- Muscular tissue
- Glandular tissue
- Epithelial tissue
What is the function of muscular tissue?
Contracts to bring about movement.
What does glandular tissue contain?
Secretory cells that can produce/release substances such as enzymes and hormones.
What is the role of epithelial tissue?
Covers the outside of the body and internal organs.
What are organs?
A group of several tissues working together to perform a specific function.
What is an organ system?
A group of organs that work together to perform specific functions.
Give examples of organ systems in humans.
- Digestive system
- Circulatory system
- Gas exchange system
What adaptations do organs have to function as exchange surfaces?
- Increased surface area
- Rich blood supply
- Short diffusion distances
- Mechanisms to increase concentration gradients
Fill in the blank: Cells → tissues → _______ → organ systems → organism.
organs
What is the primary function of the digestive system?
To break down food into smaller, soluble molecules that can be absorbed by cells.
List the main components of the digestive system.
- Mouth
- Salivary glands
- Oesophagus
- Liver
- Stomach
- Pancreas
- Small intestines
- Large intestines
- Rectum
- Anus
What role does the mouth play in digestion?
Physically breaks down food into smaller pieces.
What do salivary glands produce?
Saliva that contains enzymes.
What is the function of the oesophagus?
It is a tube that food travels down to the stomach.
What is the liver’s role in digestion?
Releases bile into the small intestine to help digest fats.
How does the stomach contribute to digestion?
Food is churned with acids and enzymes.
What is the function of the pancreas in digestion?
Produces enzymes such as lipase, amylase, and protease.
What occurs in the small intestines?
Small soluble molecules are absorbed into the bloodstream.
What is the main function of the large intestines?
Main site of water absorption.
Where is faeces stored before it is passed out of the body?
In the rectum.
What is the function of the anus?
Muscular ring through which faeces passes out of the body.
What is the function of amylase?
Breaks down carbohydrates into simple sugars.
Where is amylase used in the body?
In the pancreas, small intestine, and salivary glands.
What does protease break down?
Protein into amino acids.
Where is protease used?
In the pancreas, small intestine, and stomach.
What is the role of lipase?
Breaks down lipids into glycerol and fatty acids.
Where is lipase produced?
In the pancreas and small intestine.
What is bile and what is its function?
Not an enzyme; increases pH for lipase and emulsifies lipids.
Where is bile stored?
In the gallbladder.
Fill in the blank: The pancreas and small intestine produce three enzymes: lipase, amylase, and _______.
protease
What are the vital components of a diet that make up the structure of a cell?
Carbohydrates, lipids, and proteins
These components are essential for cell metabolism.
What are the main functions of carbohydrates?
- Provide us with fuel
- Make all other reactions of life possible
- Contain chemical elements carbon, hydrogen, oxygen
- Used in cellular respiration to provide energy for other metabolic reactions
Carbohydrates are crucial for energy metabolism.
What is the best-known single sugar?
Glucose (C6H1206)
Glucose is a fundamental energy source for cells.
What are small carbohydrate units called?
Simple sugars
These are the building blocks of carbohydrates.
What are complex carbohydrates made of?
Long chains of simple sugar units bonded together
Examples include starch and cellulose.
Give examples of carbohydrates.
- Bread
- Potatoes
- Rice
Most carbohydrates are broken down into glucose.
What are the primary uses of lipids?
- Fats and oils
- Efficient energy store and source of energy
- Important in cell membranes, hormones, and nervous system
Lipids are essential for cellular structures and functions.
What is the structure of lipids?
Made up of three molecules of fatty acids joined to a molecule of glycerol
The glycerol molecule can vary.
Give examples of lipids.
- Olive oil
- Butter
- Cheese
Lipids serve as energy reserves and structural components.
What are the roles of proteins in the body?
- Building up the cells and tissues of the body
- Basis for all enzyme activity
- Structural components of tissues e.g. muscles and tendons
- Hormones e.g. insulin
- Antibodies - destroy pathogens, part of immune system
- Enzymes - act as catalysts
Proteins are vital for numerous biological functions.
What elements are proteins made of?
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
These elements are crucial for protein structure.
What are proteins made up of?
Long chains of amino acids joined together by special bonds
There are approximately twenty different amino acids.
How does the arrangement of amino acids affect proteins?
Different arrangements of amino acids determine different proteins
This leads to diverse protein functions.
What is a key characteristic of proteins as enzymes?
Make specific 3D shapes that enable other molecules to fit into the protein
The shape is crucial for enzyme function.
What can cause a protein to denature?
Sensitive to temperature and pH changes
Denaturation results in loss of function.
Give examples of proteins.
- Meat
- Fish
- Pulses
These food sources provide essential proteins.
What are enzymes?
Biological catalysts that speed up chemical reactions without being used up in the process.
Enzymes are a type of catalyst specifically found in biological systems.
What is the primary function of enzymes?
To control the rate of chemical reactions by interacting with specific substrates.
Enzymes ensure that metabolic reactions occur efficiently and at the right pace.
What are enzymes made of?
Large protein molecules formed by long chains of amino acids folded into specific shapes.
The shape of an enzyme is critical for its function, particularly its active site.
What is the lock and key theory?
A model explaining how enzymes work, where the substrate fits into the active site of the enzyme.
This theory illustrates the specificity of enzyme-substrate interactions.
List the steps of enzyme action according to the lock and key theory.
- Substrate fits into active site of enzyme
- Enzyme and substrate bind together
- Reaction takes place
- Products released from surface of enzyme
This process highlights how substrates are transformed into products through enzyme action.
What types of reactions do enzymes catalyze?
- Building large molecules from smaller ones
- Changing one molecule into another
- Breaking down large molecules into smaller ones
Each type of reaction is facilitated by specific enzymes.
What is metabolism?
The sum of all the chemical reactions occurring in the body.
Metabolism encompasses both anabolic (building) and catabolic (breaking down) reactions.
Give an example of an enzyme-catalyzed reaction that builds large molecules.
Building starch, glycogen, cellulose from glucose or lipids from fatty acids.
This process is vital for energy storage and structural components in organisms.
Give an example of a reaction where enzymes change one molecule into another.
Changing glucose to fructose or converting one amino acid to another.
These reactions are important for metabolic flexibility and resource utilization.
What is an example of an enzyme breaking down large molecules?
Breaking down carbohydrates, lipids, and proteins into constituent molecules during digestion.
This is essential for nutrient absorption and energy release.
True or False: Every cell can have chemical reactions occurring at any time.
True.
Each type of reaction is controlled by different specific enzymes to maintain cellular function.
How do enzymes contribute to cell chemistry?
They provide control that allows reactions to occur without interference from one another.
This specificity is crucial for maintaining homeostasis within the cell.
What happens to the rate of enzyme-controlled reactions as temperature increases?
The rate increases until a certain point, after which it decreases due to denaturation.
At what temperature do most enzymes work best?
37°C, which is body temperature.
What occurs to an enzyme at temperatures around 40°C?
The enzyme is denatured; its protein structure is affected, changing the shape of the active site.
What is the consequence of enzyme denaturation?
The enzyme cannot act as a catalyst, leading to a drop in the rate of reaction.
True or False: All enzymes function best at 40°C.
False
What is the maximum temperature at which some bacteria can survive?
80°C and higher.
What can happen to enzymes at very low temperatures, such as 0°C and below?
Some enzymes can survive and function.
How does pH affect enzyme action?
A change in pH affects the forces holding the protein structure, altering the shape of the active site.
What happens to the active site when pH changes?
The specific shape is lost, and the enzyme can no longer act as a catalyst.
Different enzymes work best at varying _______.
[pH levels]
What can a change in pH do to an enzyme’s activity?
It can stop the enzyme from working completely.
What are enzymes?
Enzymes are produced by specialised cells in glands and lining of the digestive system
They control the rate of chemical reactions and operate outside of the cells.
Where are digestive enzymes produced?
Digestive enzymes are produced in the salivary glands, pancreas, and lining of the digestive system
They are secreted into the digestive system to aid in digestion.
What is the function of the digestive system?
The digestive system squeezes food, breaks it into small pieces, mixes it with digestive juices, and moves it along
Different areas of the digestive system have different pH levels for enzyme efficiency.
What is the pH level of the stomach?
The stomach has an acidic pH
This acidic environment aids in protein digestion.
What type of enzymes break down carbohydrates?
Carbohydrases break down carbohydrates
The enzyme amylase catalyses this reaction.
Where is amylase produced?
Amylase is produced in the salivary glands and pancreas
It travels to the small intestine to aid in carbohydrate digestion.
What enzymes break down proteins?
Proteases break down proteins
They are produced by the stomach, pancreas, and small intestine.
Where does the breakdown of proteins into amino acids occur?
The breakdown of proteins into amino acids occurs in the stomach and small intestine
This process is facilitated by protease enzymes.
What are lipids broken down into?
Lipids are broken down into fatty acids and glycerol
This reaction is catalysed by lipase enzymes.
Where are lipase enzymes produced?
Lipase enzymes are produced in the pancreas
They pass into the small intestine to aid in fat digestion.
What happens to digested food molecules?
They leave the small intestine and pass into the bloodstream
This allows them to be carried to the cells that need them.
Fill in the blank: _______ break down carbohydrates.
Carbohydrases
Fill in the blank: The breakdown of proteins into amino acids takes place in the _______ and _______.
stomach, small intestine
True or False: The small intestine has an acidic pH.
False
The small intestine is slightly alkaline.
What is the role of muscles in the digestive system?
Muscles move food along the digestive tract
They help in mixing food and digestive juices.
What do proteases require to work effectively?
Acidic conditions
Proteases work best in acidic conditions found in the stomach due to hydrochloric acid.
What substance does the stomach produce to protect its walls from acid and enzymes?
Thick layer of mucus
This mucus layer prevents the stomach from being digested by its own acid and enzymes.
Where are some enzymes that catalyse digestion in the small intestine produced?
Pancreas
These enzymes work best in an alkaline environment.
What is the role of bile in the digestive system?
Neutralises acid and provides alkaline conditions
Bile is produced by the liver and stored in the gallbladder, then squirted into the small intestine.
What process does bile perform on fats in food?
Emulsifies fats
This process breaks up large drops of fat into smaller droplets, increasing surface area for lipase action.
What is the pathway for bile from the gallbladder to the small intestine?
Liver and gallbladder → bile duct → pancreatic duct → duodenum
This pathway illustrates how bile reaches the site of digestion.
Why is a larger surface area important for enzymes?
To work on food more effectively
A larger surface area allows enzymes to chemically break down food more quickly.
Fill in the blank: Proteases work best in _____ conditions.
acidic
This is essential for their effective function in the stomach.
True or False: The stomach produces bile.
False
Bile is produced by the liver and stored in the gallbladder.
What happens to the acidic liquid coming from the stomach in the small intestine?
It becomes alkaline
This change is necessary for enzyme activity in the small intestine.
What is lipase’s role in digestion?
Breaks down fats into fatty acids and glycerol
Lipase works more effectively when fats are emulsified into smaller droplets.
