Organisation Flashcards
What is tissue in biological terms?
Tissue is a group of similar cells that work together to perform a specific function.
What does glandular tissue do?
Glandular tissue is responsible for making and secreting chemicals like enzymes and hormones.
What is the function of epithelial tissue?
Epithelial tissue covers body surfaces, such as skin and the lining of the intestines.
How is an organ defined?
An organ is a group of different tissues that work together to perform a particular function.
What is muscle tissue responsible for?
Muscle tissue contracts and relaxes to facilitate movement in different parts of the body.
What types of tissues can form an organ?
An organ can be formed by combinations of epithelial, muscular, and glandular tissues
What is the role of the digestive system?
The digestive system digests food and absorbs nutrients through organs like the stomach, pancreas, and liver.
What is a unique feature of specialized cells?
Specialized cells have distinct structures and functions tailored to their specific roles within tissues.
What constitutes an organ system?
An organ system is a group of organs that work together to perform a specific function.
What is the purpose of the endocrine system?
The endocrine system regulates bodily functions through the secretion of hormones.
What is the function of the cardiovascular system?
The cardiovascular system is responsible for transporting blood and nutrients throughout the body.
What are the components of the digestive system?
The digestive system includes organs like the stomach, intestines, pancreas, and liver.
What are organelles?
Organelles are subcellular structures that make up a cell, each with a specific role.
What is the role of enzymes in living cells?
Enzymes catalyze numerous chemical reactions necessary for cell function, significantly speeding up these processes.
Define a catalyst in the context of chemical reactions.
A catalyst is a substance that increases the speed of a chemical reaction without being changed or consumed in the process.
What are enzymes composed of?
Enzymes are large proteins made up of long chains of amino acids.
How does the sequence of amino acids affect enzymes?
The specific sequence of amino acids determines the unique shape of the enzyme, which is crucial for its function.
What is the function of the active site in an enzyme?
The active site is a region of the enzyme with a unique shape that is complementary to the substrates, facilitating the reaction.
What happens if a substrate does not fit the active site of an enzyme?
If the substrate does not fit the active site, the reaction will not be catalyzed.
Describe the lock and key model of enzyme action.
The lock and key model suggests that substrates fit perfectly into the active site of an enzyme, similar to how a key fits into a lock.
How does the lock and key model differ from the induced fit model?
The lock and key model describes a rigid fit, while the induced fit model describes a flexible enzyme that adjusts to the substrate.
What is the significance of enzymes being reusable?
Enzymes can catalyze multiple reactions without being used up, making them efficient biological catalysts.
Why is temperature increase not a feasible method to speed up reactions in living cells?
Increasing temperature can require excessive energy, damage cells, and accelerate non-useful reactions.
What is the role of enzymes in living organisms?
Enzymes facilitate numerous chemical reactions necessary for cellular function by increasing reaction rates.
How does temperature affect enzyme activity?
As temperature increases, enzyme activity increases until approximately 37°C, after which high temperatures lead to denaturation and a decline in activity.
What is denaturation in enzymes?
Denaturation occurs when an enzyme’s active site changes shape to the point where it can no longer bind to its substrate.
How does pH affect enzyme activity?
Extreme pH levels can decrease enzyme activity by breaking bonds that maintain the enzyme’s structure, leading to denaturation.
What is the optimal pH for enzymes?
The optimal pH is the pH level at which an enzyme functions best, varying by enzyme, with many human enzymes optimal around pH 7 and stomach enzymes around pH 2.
What is the relationship between kinetic energy and enzyme activity?
Increased kinetic energy from higher temperatures leads to more frequent and energetic collisions between enzyme and substrate, enhancing reaction rates.
What occurs to the active site of an enzyme when it denatures?
The active site changes shape significantly, preventing the substrate from binding and halting the catalytic activity of the enzyme.
Why do different enzymes have different optimum temperatures?
Different enzymes have different optimum temperatures based on their specific structural properties and the environments in which they function.
What are the primary sources of carbohydrates?
Carbohydrates are primarily found in starchy foods like bread, pasta, potatoes, and also in fruits and vegetables.
What is the main role of carbohydrates in the body?
Carbohydrates serve as the primary energy source for the body to carry out chemical reactions and physical activities.
How are lipids categorized?
Lipids are categorized into fats, which are solid at room temperature, and oils, which are liquid at room temperature.
What are the main sources of lipids?
Lipids are mainly found in oily fish, nuts, seeds, dairy products, and avocados.
What are the key roles of lipids in the body?
Lipids provide energy, serve as long-term energy storage, insulate the body, and protect organs.
What is the function of proteins in the body?
Proteins act as building blocks for growth, repair damaged tissue, and can serve as an energy source in emergencies.
What foods are rich in protein?
Protein is found in nuts, seeds, meat, fish, and legumes such as lentils and beans.
What differentiates vitamins from minerals?
Vitamins are organic molecules made by living organisms, while minerals are inorganic and simpler molecules.
What is the importance of Vitamin A
Vitamin A is crucial for good vision and maintaining healthy skin and hair.
What is the role of Vitamin C?
Vitamin C is essential for preventing scurvy and is found in fruits and vegetables, especially citrus fruits.
How does Vitamin D benefit the body
Vitamin D helps the body absorb calcium and can be produced by the body through sunlight exposure.
What are the sources and benefits of calcium?
Calcium is found in dairy products and leafy vegetables and is necessary for maintaining strong bones.
What role does iron play in the body?
Iron is a critical component of hemoglobin, which transports oxygen in red blood cells.
What is fiber and why is it significant?
Fiber is a type of carbohydrate that aids in food movement through the intestines and prevents digestive issues.
What is the primary role of water in the body?
Water is essential for many chemical reactions in the body and constitutes about 70% of the body’s composition.
Why do we need enzymes to break down carbohydrates, proteins, and lipids?
Enzymes are required to break down large biological molecules into smaller, soluble molecules that can be absorbed into the bloodstream.
What is starch and how is it broken down?
Starch is a polymer of glucose that is broken down by the enzyme amylase into maltose, which is then further broken down by maltase into glucose.
What are proteases and what do they do?
Proteases are enzymes that break down proteins into amino acids.
What are lipids and how are they broken down?
Lipids, which include fats and oils, are broken down by lipase enzymes into glycerol and fatty acids.
What role does bile play in lipid digestion?
Bile emulsifies large lipid droplets into smaller droplets, increasing the surface area for lipase action.
Where are amylase enzymes produced?
Amylase is produced in the pancreas, small intestine, and salivary glands.
Where are protease enzymes produced?
Proteases are produced in the pancreas, small intestine, and stomach.
Where are lipase enzymes produced?
Lipase is produced in the pancreas and small intestine.
What are the smaller molecules that carbohydrates are broken down into?
Carbohydrates are broken down into glucose molecules.
What is the function of enzymes in digestion?
Enzymes speed up the rate of chemical reactions required for the digestion of food.
How do enzymes facilitate the absorption of nutrients?
Enzymes break down food into smaller, soluble molecules that can be easily absorbed through the villi of the small intestine.
What are the two main roles of the digestive system?
The digestive system is responsible for digestion and absorption.
Define digestion in the context of the digestive system.
Digestion is the process of breaking down large food molecules into smaller molecules.
Define absorption in the digestive system.
Absorption is the process of taking small molecules, vitamins, minerals, and water from the digestive tract into the bloodstream.
What is the role of the teeth in digestion?
Teeth physically break down food by chewing, increasing its surface area for enzymatic action.
What is the function of salivary glands in the mouth?
Salivary glands release saliva, which contains amylase to digest starch into maltose.
How does the esophagus function in the digestive process?
The esophagus is a muscular tube that transports food from the mouth to the stomach.
What are the three main functions of the stomach?
The stomach contracts to mix food, produces pepsin to digest proteins, and secretes hydrochloric acid to kill bacteria and activate pepsin.
What is the role of the pancreas in digestion?
The pancreas releases pancreatic juices containing digestive enzymes into the small intestine.
What is the function of bile in digestion?
Bile neutralizes stomach acid and emulsifies lipids, increasing their surface area for digestion.
Where is bile produced and stored?
Bile is produced in the liver and stored in the gall bladder until needed.
Why is the small intestine considered the most important part of the digestive system?
The small intestine is where most digestion occurs and where nutrient absorption into the bloodstream takes place.
What types of enzymes are released by the small intestine?
The small intestine releases carbohydrases, lipases, and protease enzymes for digestion.
What are villi and their significance in the small intestine?
Villi are tiny finger-like projections that increase surface area for nutrient absorption.
What is the first step in preparing a food sample for testing?
Break up the food using a mortar and
Break up the food using a mortar and pestle.
How do you dissolve the crushed food in the preparation process?
Transfer the crushed food into a beaker with distilled water and stir with a glass rod.
What is the purpose of filtering the food sample solution?
To remove solid particles and obtain a clear solution for testing.
What does the Benedict’s test specifically detect?
Reducing sugars, a type of carbohydrate.
What color indicates the absence of reducing sugars in the Benedict’s test?
Blue.
What are the possible colors indicating the presence of reducing sugars in the Benedict’s test?
Green, yellow, or brick red, depending on concentration
What does the iodine test detect?
The presence of starch in a food sample.
What color change indicates the presence of starch in the iodine test?
From browny-orange to blue-black.
What does the Biuret test identify?
The presence of proteins in a food sample.
What color indicates the presence of proteins in the Biuret test?
Change from blue to pink or purple.
What is the Sudan III test used for?
To detect the presence of lipids in a food sample.
What indicates the presence of lipids in the Sudan III test?
A bright red layer forms at the top of the solution.
What indicates the presence of lipids in the Emulsion test?
A cloudy white color forms after adding distilled water.
What is the procedure to perform the iodine test?
Add 5 cm³ of food sample to a test tube, then add a few drops of iodine solution and shake gently.
What is the procedure to perform the Biuret test?
Add 2 cm³ of food sample and 2 cm³ of Biuret solution to a test tube and shake gently.
What is the primary role of the lungs?
The primary role of the lungs is to facilitate gas exchange, ensuring cells receive the oxygen needed for cellular respiration.
Describe the pathway of air during inhalation.
Air travels through the mouth or nose, down the trachea, into the bronchi, through the bronchioles, and finally reaches the alveoli.
What is a key structural feature of alveoli that aids in gas exchange?
Alveoli are composed of a single layer of very thin cells, creating a short diffusion pathway for gases.
How does the surface area of alveoli contribute to their function?
The large surface area of alveoli, due to hundreds of millions present, enhances the efficiency of gas exchange.
Why are the walls of alveoli moist?
The moist walls of alveoli allow gases to dissolve, increasing their rate of diffusion into the blood.
What happens to deoxygenated blood in the lungs?
Deoxygenated blood arrives in the lungs with low oxygen levels, allowing oxygen to diffuse into it from the alveoli.
Explain the concentration gradient’s role in gas exchange in the alveoli.
The concentration gradient allows fresh oxygen in the alveoli to diffuse into the blood, while carbon dioxide diffuses from the blood into the alveoli.
How is carbon dioxide transported in the blood?
Carbon dioxide is dissolved in blood plasma, rather than being carried by red blood cells like oxygen.
What characterizes the gas exchange process in the lungs?
Gas exchange is a continuous process with deoxygenated blood constantly entering the capillaries and oxygenated blood leaving.
Define breathing rate.
Breathing rate is the number of breaths taken per minute.
What are the four chambers of the heart?
The four chambers of the heart are the right atrium, right ventricle, left atrium, and left ventricle.
What ensures that blood flows in one direction through the heart?
The atrio-ventricular valves ensure that blood flows in one direction from the atria to the ventricles.
How does the left ventricle differ from the right ventricle?
The left ventricle has a thicker muscular wall than the right ventricle because it pumps blood throughout the entire body.
What are coronary arteries?
Coronary arteries are small arteries that branch off the aorta, supplying the heart muscle with oxygenated blood.
What are the components of the circulatory system?
The circulatory system comprises the heart, blood vessels, and blood.
What is the function of the pulmonary vein?
The pulmonary vein carries oxygenated blood from the lungs to the left atrium.
What happens when the left atrium contracts?
When the left atrium contracts, it pumps blood into the left ventricle.
How does oxygenated blood return to the heart?
Oxygenated blood returns to the heart via the pulmonary vein into the left atrium.
What is the sequence of blood flow starting from the body tissues?
Blood flows from body tissues to the vena cava, enters the right atrium, moves to the right ventricle, is pumped to the lungs, returns to the left atrium, moves to the left ventricle, and is pumped to the body via the aorta.
What is the primary function of the circulatory system?
The primary function of the circulatory system is to transport substances such as oxygen, nutrients, cells, and waste products throughout the body
From which chamber does the right ventricle receive blood?
The right ventricle receives blood from the right atrium.
What is the role of the pulmonary artery?
The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs for oxygenation.
Why is the left ventricle muscular wall thicker?
The left ventricle has a thicker muscular wall to generate the higher pressure needed to pump blood throughout the entire body.
What is the role of blood vessels in the circulatory system?
Blood vessels contain and direct blood throughout the body.
What is the function of blood in the circulatory system?
Blood serves as the fluid that carries oxygen, nutrients, cells, and waste products throughout the body.
What is the function of the vena cava?
The vena cava is the body’s largest vein, carrying deoxygenated blood from the body to the right atrium
What can happen if coronary arteries become blocked?
Blockage of the coronary arteries can lead to coronary artery disease or a heart attack.
What distinguishes a double circulatory system?
A double circulatory system consists of two separate circuits: the pulmonary circuit and the systemic circuit.
What does the aorta do?
he aorta is the largest artery in the body, carrying oxygenated blood from the left ventricle to the body.
what is the Blood pressure in capillaries like
Blood pressure in capillaries is lower than in arteries, resulting in slower blood flow.
Function of veins
Veins transport blood back to the heart.
Adaptations of capillaries
Capillary walls are one cell thick and permeable, allowing easy diffusion of substances.
Elasticity of blood vessels
Arteries have high elasticity, capillaries have low elasticity, and veins have low elasticity.
Importance of valves in veins
Valves in veins prevent backflow, ensuring blood flows toward the heart.
Structure of veins
Veins have large lumens and thin walls with small layers of elastic fibers and smooth muscle.
Comparison of wall thickness in blood vessels
Arteries have thick walls, capillaries have walls one cell thick, and veins have thin walls.
Function of capillaries
Capillaries are small vessels that exchange nutrients and oxygen with body cells and remove waste products.
Comparison of lumen size in blood vessels
Arteries have smaller lumens, capillaries have tiny individual lumens but a large total cross-sectional area, and veins have large lumens.
What are the four main components of blood?
The four main components of blood are red blood cells, white blood cells, platelets, and plasma.
What is the primary function of red blood cells (RBCs)?
The primary function of red blood cells is to carry oxygen from the lungs to the body’s tissues.
How do red blood cells adapt to maximize oxygen transport?
Red blood cells adapt by lacking a nucleus, providing more space for hemoglobin, and having a biconcave shape for a larger surface area.
What pigment is found in red blood cells and what is its role?
Red blood cells contain hemoglobin, which combines with oxygen
What are the three primary defense mechanisms used by white blood cells?
The three primary defense mechanisms are phagocytosis, producing antibodies, and producing antitoxins.
What is the primary role of white blood cells?
White blood cells are essential for the immune system, defending the body against infections.
What is the function of platelets in blood?
Platelets function to clot blood and prevent excessive bleeding during injuries.
What is plasma and what is its role in blood?
Plasma is a pale, straw-colored liquid that constitutes over half of blood’s volume and carries cells, nutrients, waste products, hormones, and proteins.
What nutrients and waste products does plasma carry?
Plasma carries nutrients like glucose and amino acids, as well as waste products like carbon dioxide and urea.
What is the process called when platelets help to stop bleeding?
The process is called clotting.
What is artificial blood and its primary benefit?
Artificial blood is a blood substitute made of salt water, primarily used to add volume to the circulatory system.
What is a major drawback of artificial blood?
A major drawback of artificial blood is that it does not contain red blood cells, limiting its ability to transport oxygen.
What is a blood transfusion?
A blood transfusion involves administering real blood from donors, which contains red blood cells necessary for oxygen transport.
What is the significance of red blood cells in a blood transfusion?
Red blood cells are significant in a blood transfusion because they are crucial for surviving blood loss by transporting oxygen.
What is cardiovascular disease?
Cardiovascular disease refers to diseases affecting the cardiovascular system, primarily the heart and blood vessels.
What causes coronary heart disease?
Coronary heart disease is caused by the blockage of coronary arteries due to the buildup of fatty material.
What are the consequences of narrowed coronary arteries?
Narrowed coronary arteries lead to reduced blood flow, less oxygen to the heart muscle, and potential heart strain or attacks.
What are stents used for?
Stents are expandable tubes placed inside arteries to keep them open and ensure continuous blood flow.
What are the benefits and downsides of stents?
Benefits include quick surgery and long-term effectiveness, while downsides include surgical risks and potential thrombosis.
What are statins and their function?
Statins are medications that lower bad cholesterol (LDL) and increase good cholesterol (HDL) to reduce the risk of heart disease.
What issues can arise with faulty heart valves?
faulty heart valves can lead to insufficient blood flow or backward leakage of blood due to improper closure.
What are the treatment options for heart failure?
Treatment options for heart failure include medications and heart transplants, with transplants being the definitive solution.
What is heart failure
Heart failure occurs when the heart cannot pump blood effectively around the body.
What challenges are associated with heart transplants?
Challenges include the difficulty of finding a suitable donor heart and the risk of immune rejection of the donor heart.
What are the two main problems with heart valves?
The two main problems are stiffness that restricts blood
The two main problems are stiffness that restricts blood flow and improper closure that allows blood to leak backwards.
What can cause damage to heart valves?
Heart valves can be damaged by aging, heart attacks, or infections.
What is the advantage of artificial hearts over biological hearts?
Artificial hearts are made of metal and plastic, making them less likely to be rejected by the immune system.
How can faulty heart valves be treated?
Faulty heart valves can be treated by replacing them with biological or mechanical valves.
What are the side effects of statins?
Side effects of statins can include headaches and kidney failure, and they must be taken regularly for years.
What types of risk factors are associated with non-communicable diseases?
Risk factors can be categorized into lifestyle aspects (like obesity, diet, smoking, and lack of exercise) and substances in the body or environment (such as air pollution and toxins).
What role do interactions between risk factors play in disease development?
Multiple risk factors can interact to influence the development of a particular disease, such as diet, obesity, smoking, and lack of exercise contributing to cardiovascular disease.
How does obesity function as a risk factor for diseases?
Obesity, often resulting from poor lifestyle choices, is a risk factor for diseases like type 2 diabetes and cardiovascular disease.
What are the two types of tumors?
The two types of tumors are benign and malignant.
What is a tumor?
tumor is an abnormal mass of cells that forms when a group of cells undergo uncontrolled growth and division.
What role do interactions between risk factors play in disease development?
Multiple risk factors can interact to influence the development of a particular disease, such as diet, obesity, smoking, and lack of exercise contributing to cardiovascular disease.
What distinguishes malignant tumors from benign tumors?
Malignant tumors can invade other tissues and spread to different parts of the body, while benign tumors remain contained.
Why are malignant tumors classified as cancer?
Malignant tumors are classified as cancer because they can cause significant damage and are potentially fatal.
What is the relationship between smoking and cancer?
Smoking is linked to various cancers, including lung, mouth, stomach, and cervical cancer.
How does obesity relate to cancer risk?
Obesity is associated with an increased risk of several cancers, including bowel, liver, and kidney cancer.
What is the effect of ultraviolet light exposure on cancer risk?
Ultraviolet light exposure is strongly linked to an increased risk of skin cancer due to damage to skin cells.
How does alcohol consumption affect cancer risk?
Drinking alcohol is linked to an increased risk of liver cancer.
What role do inherited genes play in cancer susceptibility?
Inherited genes can increase susceptibility to certain cancers, such as the BRCA genes linked to breast and ovarian cancer.
Levels of organization in plants
Plants have levels of organization including cells, tissues, organs, and organ systems.
Function of leaves in plants
Leaves are primarily responsible for photosynthesis, converting carbon dioxide and water into sugars.
Role of stomata in leaves
Stomata are small
Role of stomata in leaves
Stomata are small openings that allow carbon dioxide to enter the leaf for photosynthesis.
Composition of the lower epidermis
The lower epidermis is a layer of hypodermal tissue containing numerous stomata.
Function of spongy mesophyll tissue
Spongy mesophyll tissue facilitates gas diffusion due to its air gaps between cells.
Function of palisade mesophyll layer
The palisade mesophyll layer is where the majority of photosynthesis occurs, containing many chloroplasts.
Role of upper epidermis in leaves
The upper epidermis allows sunlight to pass through to the chloroplasts in the palisade cells.
Function of phloem in plants
Phloem transports sugars produced in the leaves to other parts of the plant.
Waxy cuticle function
The waxy cuticle is a waterproof layer that reduces water loss from the leaf.
How guard cells regulate stomata
Guard cells control the size of stomata openings to balance carbon dioxide intake and water loss.
What is translocation in plants?
Translocation is the process of transporting sugars produced in the leaves to other parts of the plant for energy or storage.
How do phloem cells facilitate sugar transport?
Phloem cells are arranged end to end to form phloem tubes, with small pores between them that allow the movement of cell sap, a mixture of water and sugar.
What are the two main uses of sugars once they reach destination cells?
Sugars can be used directly for energy or stored for later use.
What is the primary function of xylem tubes?
Xylem tubes transport water and mineral ions from the roots to the leaves, where water is used in photosynthesis.
How does transpiration drive water movement in plants?
Transpiration drives water movement by the evaporation of water from leaves, creating a pull that drags the water chain upward through the xylem.
Define transpiration in plants.
Transpiration is the evaporation of water from the leaves of a plant.
What is the transpiration stream?
The transpiration stream is the continuous chain of water molecules being pulled upward through the plant as water evaporates from the leaves.
List the four main factors influencing the rate of transpiration.
the four main factors are light intensity, temperature, air flow, and humidity.
How does light intensity affect the rate of transpiration?
Higher light intensity increases photosynthesis, causing more stomata to open, which raises water evaporation and transpiration rates.
What effect does temperature have on transpiration?
Warmer temperatures increase the rate of transpiration because water particles have more energy and are more likely to evaporate.
Explain how air flow influences transpiration rates.
High air flow removes water molecules from around the leaf, maintaining a high concentration gradient that increases the rate of transpiration
How does humidity affect the transpiration rate?
High humidity reduces the concentration gradient between the inside and outside of the leaf, decreasing the rate of transpiration.
What is the role of stomata in transpiration?
Stomata are openings on the leaf surface that allow for gas exchange and water evaporation, facilitating transpiration
What is lignin and its role in xylem cells?
Lignin is a strengthening material that reinforces xylem cells, allowing them to effectively transport water.
Describe the arrangement of xylem cells.
Xylem cells are dead and lack ends between them, forming a continuous hollow tube for efficient water transport.
