Structure and Functions in living organisms

(Most of the notes on topic 2, this set is unfinished)

What are cells?

Basic units composing living organisms.

Define unicellular organisms?

Organisms consisting of a single cell.

Explain multicellular organisms?

Organisms composed of multiple cells.

What is the organizational order in complex multicellular organisms?

Organelle level, cellular level, tissue level, organ level, organ system level, and organism level.

Define organelle?

Cellular components executing specific tasks.

Define tissues?

Groups of cells with similar structures fulfilling specific functions.

Define organ system?

Collection of organs with interrelated functions.

Provide an example of an organ system?

Respiratory system.

What is the function of the digestive system?

Nutrient provision to the body.

What does the respiratory system do?

Supplies oxygen and eliminates carbon dioxide.

Identify the level of organization above the organ system level?

Organism level.

Offer an example of an organ at the organ level?

Brain.

Give an instance of a tissue at the tissue level?

Nervous tissue.

Provide an example of an organelle?

Nucleus

How do cells contribute to living organisms' organization?

By forming fundamental structural units.

What is the highest level of organization in living organisms?

Organism level.

Offer an example of an organism?

Elephant.

What role do tissues play in multicellular organisms?

Execution of specific functions collectively.

Define cells?

Basic units of life.

What defines unicellular organisms?

Being comprised of a lone cell.

Describe multicellular organisms?

Comprising numerous cells.

How is the organizational order structured in complex multicellular organisms?

Organelle level, cellular level, tissue level, organ level, organ system level, organism level.

Define organelle?

Specialized structures within cells carrying out specific functions.

Define tissues?

Groups of cells with similar structures and functions.

Define organ system?

Group of organs collaborating to carry out a particular function.

What separates cells from their surrounding environment?

Cell membrane.

What is contained within the cell membrane?

Cytoplasm

What do eukaryotic cells have within their cytoplasm?

Organelles.

What are organelles?

Specialised unit within a cell which performs a specific function.

Name some organelles found in the cytoplasm of eukaryotic cells?

Nucleus, mitochondria, ribosomes.

What additional structures do plant cells contain?

Cell wall, chloroplasts, permanent vacuole.

What is visible when viewing the structures inside a plant cell under a microscope?

Ribosomes and mitochondria are not visible, but other structures are visible.

Define nucleus?

Contains genetic material controlling cell growth, function, and division.

Define cytoplasm?

Supports cell structures, hosts chemical reactions, and contains water and solutes.

Define cell membrane?

Maintains cell integrity and regulates substance passage.

Define cell wall?

Provides additional support and defines cell shape?

Define chloroplasts?

Sites of photosynthesis, containing chlorophyll for light absorption.

Define vacuole?

Contains cell sap, aids in material storage, and maintains cell shape.

Define mitochondria?

Sites of aerobic respiration, providing cellular energy.

Define ribosomes?

Sites of protein synthesis.

What are the main subcellular structures in animal cells?

Nucleus, cell membrane, mitochondria, ribosomes, cytoplasm.

What additional subcellular parts do plant cells have?

They have a cell wall, chloroplasts, and a permanent vacuole.

Describe the structure and function of the cell wall? (Plant Cell)

They provide structural support and define shape in plant cells.

Explain the role of chloroplasts in plant cells?

They are responsible for photosynthesis, utilizing light energy to produce glucose.

Describe the permanent vacuole in plant cells?

They store cell sap and maintain turgor pressure in plant cells.

What is cell differentiation?

It is the process where a cell becomes specialized for a particular function.

How do cells differentiate in multicellular organisms?

They develop specific structures and functions to perform specialized roles.

What happens during differentiation of a nerve cell?

They elongate to form connections over large distances for signal transmission.

When do animal cells lose their ability to differentiate?

Mostly in early in development.

What are adult stem cells?

They replenish tissues and are involved in repair throughout life.

How do plants differ from animals regarding cell differentiation?

Many types of plant cells retain the ability to differentiate throughout life.

What controls the differences between specialized cells?

Genes in the nucleus.

Describe the structure of nerve cells? (Animal Cell)

They have elongated extensions for signal transmission.

Explain the structure of red blood cells? (Animal Cell)

They are biconcave for efficient oxygen diffusion and have no nucleus

What are the characteristics of sperm cells?

They have tails for movement and enzymes for egg penetration.

Describe the structure of egg cells (ovum)?

They contain lots cytoplasm for embryo growth

Describe the root cells in plants?

They have lots of it for increased water absorption.

Explain the structure of? (Plant Cell)

They lack walls between vessels for continuous water flow.

What are the characteristics of palisade mesophyll cells? (Plant Cell)

They are column shaped with abundant chloroplasts.

What is contained within the cell membrane? (Both)

Cytoplasm.

What do eukaryotic cells have within their cytoplasm?

Organelles.

Name some organelles found in the cytoplasm of eukaryotic cells?

Nucleus, mitochondria, and ribosomes.

What is visible when viewing the structures inside a plant cell?

Chloroplasts and the cell wall.

What is the highest level of organization in organisms?

Organism level.

What do you call anything that contains carbon?

Organic molecules.

What 3 molecules contain carbon?

Carbohydrates, Lipids, Proteins.

What are large molecules made of?

Smaller molecules.

What 3 elements do carbohydrates contain?

Carbon, hydrogen, oxygen.

Monosaccharides are the simplest form of what?

Carbohydrates.

Is a monosaccharide a complex sugar? (Carbohydrates)

No, it’s a simple sugar.

What are 2 examples of monosaccharides? (Carbohydrates)

Glucose and Fructose.

When is a disaccharide made? (Carbohydrates)

When 2 monosaccharides join together.

What is formed from 2 glucose molecules? (Carbohydrates)

Maltose.

What is formed from one glucose and one fructose molecule? (Carbohydrates)

Sucrose.

When is a polysaccharide formed? (Carbohydrates)

When lots of monosaccharides join together.

What 3 things are all formed when lots of glucose molecules join together? (Carbohydrates)

Starch, glycogen, cellulose.

Are polysaccharides soluble and why does this make it useful? (Carbohydrates)

Insoluble so it’s useful as storage molecules.

What is another term for fats?

Lipids.

What are most fats (lipids) in the body made of?

Triglycerides.

What is the basic unit of a fat?

1 glycerol molecule chemically bonded to 3 fatty acid chains.,

What do fatty acids vary in?

Size and structure.

What are the 2 things that lipids can be divided into?

Fats (solid at room temperature) and oils (liquid at room temperature

What are proteins formed from?

Long chains of amino acids.

How many different types of amino acids are there?

20.

What is formed when amino acids are joined together?

Protein.

Give 3 examples of Proteins?

Enzymes, haemoglobin, ligaments.

What does an Amino acid form before it becomes a Protein?

Peptide.

What do different proteins have?

Different amino acids which means they are different shapes.

Is it true that even a small difference in the amino acid sequence of a protein will result in a very different protein being formed?

Yes.

The __ of a protein determines its function?

Shape, e.g the shape of the active size of an enzyme to fit for a reaction (by being complementary) to happen//shape of antibody to bind to antigen.

How should you prepare a solid food sample before conducting food tests?

Break up the food using a pestle and mortar, transfer to a test tube, add distilled water, mix, and filter the mixture.

What should you add to a sample solution to test for glucose?

Add Benedict's solution.

What is the next step after adding Benedict's solution to the sample solution?

Heat in a boiling water bath for 5 minutes.

How can you recognize a positive test for glucose using Benedict's solution?

A positive test shows a color change from blue to orange/brick red.

What substance is used to test for the presence of starch in a food sample?

Iodine solution.

How do you recognize a positive test for starch with iodine solution?

A positive test shows a color change from orange-brown to blue-black.

What solution should you add to the food sample to test for protein?

Add Biuret solution.

How do you recognize a positive test for protein with Biuret solution?

A positive test shows a color change from blue to violet/purple.

What is the procedure for testing for lipids?

Mix the food sample with ethanol, allow it to dissolve, strain into another test tube, add an equal volume of cold distilled water, and observe for a cloudy emulsion.

What indicates a positive test for lipids?

The formation of a cloudy emulsion after mixing the ethanol-extracted solution with cold distilled water.