Microscopy Techniques and Operation

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Questions and Answers

At what temperature range does enzyme activity begin to decrease?

37-50°C

Above 50°C

25-37°C (correct)

0-25°C

Enzymes become inactive at low temperatures and cannot regain activity when temperature increases.

False

What is the optimum temperature for enzyme activity?

xxx

Enzymes are ______ at high temperatures due to denaturation.

denatured Signup and view all the answers

Match the following conditions with their effects on enzyme activity:

Low temperature = Enzyme is inactive High temperature = Enzyme is denatured Optimum temperature = Maximum enzyme activity pH variation = Changes in enzyme activity Signup and view all the answers

What purpose does distilled water serve in enzyme experiments?

To check results are due to enzyme alone Signup and view all the answers

Incubating substrate at a specific temperature helps maintain fair comparison.

True Signup and view all the answers

What does a larger diameter of the clear zone indicate in enzyme activity?

Larger enzyme activity Signup and view all the answers

What is the primary function of the ribosome in a cell?

To synthesize proteins Signup and view all the answers

The hydrophobic tails of phospholipids point outward toward the aqueous environment.

False Signup and view all the answers

What is the arrangement of phospholipids in a cell membrane?

Bilayer with hydrophilic heads outward and hydrophobic tails inward. Signup and view all the answers

Which of the following foods is NOT a source of essential amino acids?

Fruits Signup and view all the answers

Eukaryotic cells generally contain more __________ than prokaryotic cells.

organelles Signup and view all the answers

Match the following terms with their definitions:

Ribosome = Site of protein synthesis Endoplasmic Reticulum = Site of lipid synthesis and protein modification Cell Membrane = Barrier that regulates entry and exit of substances Phospholipid = Molecule that makes up the cell membrane structure Signup and view all the answers

Kwashiorkor is a condition that results from an excess of protein in the diet.

False Signup and view all the answers

What is the primary function of Vitamin A in the human body?

Formation of pigment in the retina for vision in dim light Signup and view all the answers

Which type of cell is known to have a well-defined nucleus?

Eukaryotic cell Signup and view all the answers

Smooth endoplasmic reticulum is involved in protein synthesis.

False Signup and view all the answers

The accumulation of tissue fluid in children suffering from Kwashiorkor leads to a ______ abdomen.

swollen Signup and view all the answers

Match the type of amino acids with their description:

Essential = Obtained from diet Non-essential = Produced in the body Signup and view all the answers

What is the role of the cell membrane?

To protect the cell and regulate the movement of substances in and out. Signup and view all the answers

Which nutrient is directly related to the formation of phospholipids for cell membranes?

Fats Signup and view all the answers

According to the material, there are 20 essential amino acids in the human body.

False Signup and view all the answers

Name two food sources rich in Vitamin A.

Fish liver oils, carrots Signup and view all the answers

What is the primary function of the large number of air sacs in the respiratory system?

To increase surface area for diffusion of gases Signup and view all the answers

The walls of the air sacs are thick to facilitate gas exchange.

False Signup and view all the answers

Why is it important for oxygen to dissolve in the water film inside the air sacs before diffusion?

It allows for more efficient gas exchange. Signup and view all the answers

The _______ layer of membranes is held together by pleural fluid, which also acts as a lubricant.

pleural Signup and view all the answers

What is the primary site of food absorption?

Small intestine Signup and view all the answers

Constipation occurs when too much water is absorbed from the feces.

True Signup and view all the answers

Match the following diseases with their descriptions:

Smoking = Can lead to lung cancer and respiratory diseases Covid = A viral infection affecting respiratory function Cancer = Uncontrolled growth of abnormal cells in the lungs Pneumothorax = Collapse of the lung due to air in the pleural space Signup and view all the answers

What happens to feces if water absorption is too slow?

Diarrhea Signup and view all the answers

What role do capillaries play in the gas exchange process?

They allow rapid transport of gases to and from the air sacs. Signup and view all the answers

The inner surface of the air sacs is kept dry to enhance diffusion of gases.

False Signup and view all the answers

The ___ in the digestive system is responsible for absorbing minerals and vitamins.

large intestine Signup and view all the answers

Match the intestinal parts with their functions:

Small intestine = Major site of food absorption Large intestine = Water absorption and feces formation Lacteal = Absorption of fats Colon = Final water absorption Signup and view all the answers

What is the significance of the pleural fluid during inhalation and exhalation?

It reduces friction between the pleural membranes. Signup and view all the answers

What does the term 'fluid' in the fluid mosaic model refer to?

The ability of phospholipids to move laterally Signup and view all the answers

Diffusion involves the net movement of particles from an area of high concentration to an area of low concentration.

True Signup and view all the answers

What is osmosis?

The movement of water molecules from an area of higher water potential to an area of lower water potential through a differentially permeable membrane. Signup and view all the answers

Dialysis tubing allows molecules to pass through but blocks molecules.

small, large Signup and view all the answers

What happens to the water level in dialysis tubing when placed in distilled water?

Water level rises Signup and view all the answers

A high concentration of solute decreases the water potential of a solution.

True Signup and view all the answers

Why should the outside of the dialysis tubing be rinsed with water before setting up the experiment?

To remove any contaminants or excess solute that might affect the results. Signup and view all the answers

Which food substance serves as the main energy source for body activities?

Carbohydrates Signup and view all the answers

Proteins provide energy to the body in the same way that carbohydrates do.

False Signup and view all the answers

What color indicates a positive result in the Iodine Test for starch?

blue-black Signup and view all the answers

The __________ test is used to detect the presence of vitamin C in a solution.

DCPIP Signup and view all the answers

Match the balanced diet components with their primary functions:

Carbohydrates = Energy source Proteins = Growth and repair Fats = Energy storage Vitamins = Maintain health Signup and view all the answers

What is the purpose of the grease spot test?

To determine the presence of lipids Signup and view all the answers

The iodine test results in a blue color when starch is present.

False Signup and view all the answers

What is the main reagent used in the iodine test for starch?

iodine solution Signup and view all the answers

A balanced diet consists of all food substances in the right amounts and __________.

proportions Signup and view all the answers

What color change occurs when Vitamin C is added to DCPIP solution during testing?

It becomes colorless Signup and view all the answers

What is the primary function of protein test strips?

To detect the presence of proteins in a sample Signup and view all the answers

Match the following tests to their corresponding substances:

Grease spot test = Lipids Iodine test = Starch Benedict's test = Reducing sugars Protein test strips = Proteins Signup and view all the answers

Which component of a balanced diet is essential for building body tissues, especially in children and teenagers?

Proteins Signup and view all the answers

Females require more iron than males primarily due to the loss of iron during menstruation.

True Signup and view all the answers

Vitamin D is essential for the formation of strong bones and __________.

teeth Signup and view all the answers

What is the main reason that children require more energy per unit body mass than adults?

Rapid growth Signup and view all the answers

Individuals who are more physically active require more ______ for their muscular activities.

energy Signup and view all the answers

Match the following dietary factors with their respective descriptions:

Age = Growth stage needing more energy Sex = Differences in energy and nutrient needs between genders Level of activity = Increased energy requirement due to physical exertion Nutrient composition = Essential nutrients needed for specific bodily functions Signup and view all the answers

What does the food pyramid represent?

A model for a balanced diet Signup and view all the answers

Both males and females require the same amount of protein in their diets.

False Signup and view all the answers

Name one nutrient that is particularly important for children to support their growth.

Calcium Signup and view all the answers

Study Notes

Microscopy

Light microscope:
- Shows only the nucleus, chloroplasts (chlorophyll), vacuole, and cell wall
- Magnification of 1600x
Electron microscope:
- Produces images with higher magnification and resolutions
- Allows scientists to discover the structure of cell organelles
- Magnification of 200000x (scanning) & 1500000x (transmission)
Scanning electron microscope:
- Shows 3D external structure
- Magnification of 200000x
Transmission electron microscope:
- Shows 2D internal structure
- Magnification of 1500000x

Microscope Operation

Add iodine solution to stain the specimen to make cell structures more distinct
Raise the stage/lower the body tube by turning the course adjustment knob
Search the field using the low power objective
Focus with the low power objective
Adjust the position of the slide to locate the object in the center of the field
Focus using the high power objective
Use the fine adjustment knob to sharpen the focus
Adjust the light source for a clearer view

Cell Structure

Label questions:
- Small particles = ribosomes
- Endoplasmic reticulum (rough or smooth)
- Finding organelles based on cell type.
- The function of a cell and the organelles it contains.
- Function of other cells and lack of certain organelles.
Finding the type of cell from the number of organelles it contains.
Comparing similarities and differences between two cells.

Abundance of Organelles in Different Cell Types

Cells with high mitochondria counts:
- Enzyme-secreting cells (e.g., liver cells)
- Epithelial cells of the small intestine
- Muscle cells
- Root hair cells
Cells with diverse roles and fewer mitochondria:
- Explain the differences and how it correlates with its function

Cell Membrane

Structure:
- Phospholipids arranged in a bilayer (tail-to-tail).
- Hydrophobic tails face inward, hydrophilic heads face outward.
- Proteins interspersed within the bilayer.
Permeability:
- Polar/charged molecules can pass via protein channels.
- Non-polar molecules easily diffuse through the phospholipid bilayer.

Transport Across Cell Membranes

Channel proteins: act as open pores for ion/polar molecules diffusion
Carrier proteins: bind to molecules, change shape to transfer them across
Active transport: requires ATP (energy) to move molecules against concentration gradient

Osmosis

Water potential: tendency for water to move
Factors affecting rate:
- Temperature (higher temperature=faster rate)
- Surface area (larger surface area =faster rate)
- Distance (shorter distance= faster rate

Microscopy Summary (Part 2)

Aim: to show osmosis across dialysis tubing.
Method: rinsing dialysis tubing to remove sucrose, controlling variables (same apparatus except for sucrose being replaced with water)
Results*: the rise in the tube.

Osmosis Experiment

Aim: to investigate effects of temp. on permeability of the beet root cell membrane.
Results: Higher temp = more color release

Fluid Mosaic Model

Fluid: phospholipids can move laterally
Mosaic: proteins are embedded
Diffusion: net movement of particles down the concentration gradient
Equilibrium: no net movement, but still random movement.
Materials exchange: Absorption/removal of waste, gas exchange, nutrients absorption

Cell Organization and Function

Cell components: Describe individual organelles and their role.
Specialized cells (e.g., nerve cells, muscle cells):
- Explain how their functions correlates to their structures.
Organ systems (e.g., digestive system):
- Explain how individual organs work together to perform complex processes.

Cell Types, and Organelles

Prokaryotic and Eukaryotic cells:
- Emphasize similarities and differences.

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Description

This quiz covers key concepts related to microscopy, including different types of microscopes such as light, scanning electron, and transmission electron microscopes. It also details the operation procedures for using a microscope effectively, from staining specimens to focusing on objects. Test your understanding of these essential microscopy techniques.

Microscopy Techniques and Operation

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Podcast

Questions and Answers

At what temperature range does enzyme activity begin to decrease?

Enzymes become inactive at low temperatures and cannot regain activity when temperature increases.

What is the optimum temperature for enzyme activity?

Enzymes are ______ at high temperatures due to denaturation.

Match the following conditions with their effects on enzyme activity:

What purpose does distilled water serve in enzyme experiments?

Incubating substrate at a specific temperature helps maintain fair comparison.

What does a larger diameter of the clear zone indicate in enzyme activity?

What is the primary function of the ribosome in a cell?

The hydrophobic tails of phospholipids point outward toward the aqueous environment.

What is the arrangement of phospholipids in a cell membrane?

Which of the following foods is NOT a source of essential amino acids?

Eukaryotic cells generally contain more __________ than prokaryotic cells.

Match the following terms with their definitions:

Kwashiorkor is a condition that results from an excess of protein in the diet.

What is the primary function of Vitamin A in the human body?

Which type of cell is known to have a well-defined nucleus?

Smooth endoplasmic reticulum is involved in protein synthesis.

The accumulation of tissue fluid in children suffering from Kwashiorkor leads to a ______ abdomen.

Match the type of amino acids with their description:

What is the role of the cell membrane?

Which nutrient is directly related to the formation of phospholipids for cell membranes?

According to the material, there are 20 essential amino acids in the human body.

Name two food sources rich in Vitamin A.

What is the primary function of the large number of air sacs in the respiratory system?

The walls of the air sacs are thick to facilitate gas exchange.

Why is it important for oxygen to dissolve in the water film inside the air sacs before diffusion?

The _______ layer of membranes is held together by pleural fluid, which also acts as a lubricant.

What is the primary site of food absorption?

Constipation occurs when too much water is absorbed from the feces.

Match the following diseases with their descriptions:

What happens to feces if water absorption is too slow?

What role do capillaries play in the gas exchange process?

The inner surface of the air sacs is kept dry to enhance diffusion of gases.

The ___ in the digestive system is responsible for absorbing minerals and vitamins.

Match the intestinal parts with their functions:

What is the significance of the pleural fluid during inhalation and exhalation?

What does the term 'fluid' in the fluid mosaic model refer to?

Diffusion involves the net movement of particles from an area of high concentration to an area of low concentration.

What is osmosis?

Dialysis tubing allows __________ molecules to pass through but blocks __________ molecules.

What happens to the water level in dialysis tubing when placed in distilled water?

A high concentration of solute decreases the water potential of a solution.

Why should the outside of the dialysis tubing be rinsed with water before setting up the experiment?

Which food substance serves as the main energy source for body activities?

Proteins provide energy to the body in the same way that carbohydrates do.

What color indicates a positive result in the Iodine Test for starch?

The __________ test is used to detect the presence of vitamin C in a solution.

Match the balanced diet components with their primary functions:

What is the purpose of the grease spot test?

The iodine test results in a blue color when starch is present.

What is the main reagent used in the iodine test for starch?

A balanced diet consists of all food substances in the right amounts and __________.

What color change occurs when Vitamin C is added to DCPIP solution during testing?

What is the primary function of protein test strips?

Match the following tests to their corresponding substances:

Which component of a balanced diet is essential for building body tissues, especially in children and teenagers?

Females require more iron than males primarily due to the loss of iron during menstruation.

Vitamin D is essential for the formation of strong bones and __________.

What is the main reason that children require more energy per unit body mass than adults?

Individuals who are more physically active require more ______ for their muscular activities.

Match the following dietary factors with their respective descriptions:

What does the food pyramid represent?

Both males and females require the same amount of protein in their diets.

Name one nutrient that is particularly important for children to support their growth.

Study Notes

Microscopy

Microscope Operation

Cell Structure

Abundance of Organelles in Different Cell Types

Cell Membrane

Transport Across Cell Membranes

Osmosis

Microscopy Summary (Part 2)

Osmosis Experiment

Fluid Mosaic Model

Dialysis tubing allows molecules to pass through but blocks molecules.