Yr 11 BIO - Module 1

What are the two basic categories of cells?

Prokaryotes and Eukaryotes.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells are primitive, simpler in structure, and lack a nucleus, while eukaryotic cells are more complex, larger, and have a membrane-bound nucleus.

What is the size range of prokaryotic cells?

0.1 to 5.0 micrometers (um).

What are the common components found in all prokaryotic cells?

Cell membrane, cytoplasm, ribosomes, and genetic material.

What additional structures can prokaryotic cells have?

Cell walls, pili (external hairlike structures), and flagella (whiplike tails).

What type of organisms are primarily composed of prokaryotic cells?

Unicellular organisms.

What is the size range of eukaryotic cells?

10 to 100 micrometers (um).

What characterizes eukaryotic cells?

They have a membrane-bound nucleus and all internal organelles are membrane-bound.

Can eukaryotic cells be unicellular or multicellular?

Yes, they can be either unicellular or multicellular.

How is total magnification calculated?

Total magnification = eyepiece magnification x objective magnification.

What happens to the field of view as magnification increases?

As magnification gets bigger, the field of view gets smaller.

What is the Fluid Mosaic Model?

It describes the cell membrane as a mobile oily phospholipid bilayer with embedded proteins and lipids, resembling a mosaic.

What are the components of a phospholipid?

Hydrophilic (water-loving) phosphate heads and two hydrophobic (water-hating) tails.

How do phospholipids arrange themselves in the cell membrane?

They form a bilayer with heads pointing outward towards the watery medium and tails facing inward.

What role do carbohydrates play in the cell membrane?

Carbohydrates attached to membrane proteins and lipids extend from the surface of the fluid bilayer.

What is membrane permeability?

The ability of the cell membrane to allow certain substances to pass through while blocking others.

What is the function of ribosomes in a cell?

Ribosomes are responsible for making proteins.

What is the function of mitochondria in a cell?

Mitochondria are involved in energy production.

What is the role of the nucleus in a cell?

The nucleus acts as the brain of the cell, controlling its activities.

What is the function of chloroplasts?

Chloroplasts are involved in photosynthesis.

What is cytoplasm's role in a cell?

Cytoplasm carries substances around inside the cell and allows things to pass through.

What is permeability in relation to membranes?

Permeability is the ability of a membrane to allow substances to pass through it.

What does it mean if a membrane is impermeable?

An impermeable membrane allows no molecules to pass through it and has no pores.

What is a selectively permeable membrane?

A selectively permeable membrane only allows certain molecules to pass through it, typically through small pores.

What does a permeable membrane do?

A permeable membrane allows all molecules to pass through it via large pores.

Define solvent and solute.

A solvent is a substance able to dissolve other substances, while a solute is a substance that dissolves in a solvent.

Provide an example of a solute and solvent.

Sugar is a solute that dissolves in water, which is the solvent, to create a sugar solution.

What is a dilute solution?

A dilute solution contains only a small amount of solute.

What is a concentrated solution?

A concentrated solution contains a large amount of solute.

What are the two types of transport across the cell membrane?

Active transport and passive transport.

Describe passive transport

Passive transport involves the movement of substances from high to low concentration, such as through diffusion and osmosis, without requiring cellular energy.

What is active transport?

Active transport involves the movement of substances from low to high concentration, using energy to drive their motion against concentration gradients.

What is diffusion?

Diffusion is the movement of substances from areas of high concentration to areas of low concentration along a concentration gradient

Does diffusion require cellular energy?

No, diffusion does not require cellular energy.

What types of molecules diffuse easily across cell membranes?

Gases like oxygen, nitrogen, carbon dioxide, and small molecules such as water, urea, and ethanol diffuse easily.

What is facilitated diffusion?

Facilitated diffusion is the process where large uncharged molecules like glucose and ions require assistance to pass through the cell membrane.

How do carrier proteins function in facilitated diffusion?

Carrier proteins bind to specific molecules and open and close to transport the molecules into and out of the cell.

What role do channel proteins play in facilitated diffusion?

Channel proteins open and close to control the movement of ions into and out of the cell.

What is the function of protein pumps in active transport?

Protein pumps are used to transport small molecules and ions across the cell membrane using energy.

How are large molecules transported across the cell membrane?

Large molecules such as proteins and nucleotides are transported using vesicles.

What are the two types of endocytosis?

Pinocytosis (entrance of liquids) and phagocytosis (entrance of solid particles).

What is receptor-mediated endocytosis?

Receptor-mediated endocytosis involves substances selected for ingestion binding to specific receptor sites on the membrane called coated pits.

What is osmosis?

Osmosis is the diffusion of water across a partially permeable membrane from higher water concentration to lower concentration.

What is the difference between diffusion and osmosis?

Diffusion is the movement of particles from high to low concentration, while osmosis specifically refers to the movement of water molecules.

What characterizes an isotonic solution?

Solute concentration inside equals solute concentration outside, allowing water molecules to move in and out of the cell freely, keeping cells normal.

What happens to cells in a hypotonic solution?

Water molecules move into the cell, causing cells to swell.

What occurs in a hypertonic solution?

Water molecules move out of the cell, leading to cell shrinkage.

What are enzymes?

Protein molecules that control all reactions in living cells and act as biological catalysts.

How do enzymes function in chemical reactions?

They control the rate of reactions without being consumed, allowing for reuse.

What is the significance of an enzyme's shape?

The shape must match the substrate exactly for bonding; changes in shape can block substrate binding.

What is the 'lock and key' concept in enzyme activity?

- Specific substrates bind to specific enzymes due to their complementary shapes.

What is the 'induced fit model'?

Enzymes can slightly alter their shape to better bind to the substrate during the reaction.

What happens to substrates during enzyme activity?

Substrates can either be combined or separated, with chemical bonds being formed or broken respectively.

What factors can impact enzyme activity?

Temperature, pH, and substrate concentration can affect enzyme shape and activity.

What is denaturation in the context of enzymes?

Denaturation occurs when optimal temperature or pH changes, altering the enzyme's shape and blocking substrate binding.

What causes denaturation of enzymes?

Changes in temperature and pH can disrupt hydrogen bonding among amino acids, altering the enzyme's shape.

What is photosynthesis?

The process where sunlight is captured to produce glucose through chemical reactions involving chlorophyll.

Where does photosynthesis occur in plant cells?

In the chloroplasts.

What is the role of glucose in cellular respiration?

Glucose serves as the fuel source for energy production.

What can excess glucose be stored as in plants and humans?

As starch or cellulose in plants, and as glycogen in humans.

What are the three membranes of chloroplasts?

Outer membrane, inner membrane around the stroma, and thylakoid membrane.

What is the function of thylakoids in chloroplasts?

They are involved in light-dependent reactions of photosynthesis.

What occurs in the stroma of chloroplasts?

Light-independent reactions take place here, where glucose is produced.

What are the reactants of the photosynthesis equation?

Water and carbon dioxide.

What is the role of chlorophyll in photosynthesis?

Chlorophyll is required to trap the energy of sunlight, allowing reactants to rearrange into glucose and oxygen.

What are the two main processes of photosynthesis?

Photosynthesis consists of light dependent reactions and light independent reactions.

Where do light dependent reactions occur?

Light dependent reactions occur in the thylakoids of the chloroplasts.

What products are generated from light dependent reactions?

The light dependent reactions produce ATP, NADPH, hydrogen ions, and oxygen molecules.

What is the Calvin Cycle?

The Calvin Cycle is a process in the light independent reactions that uses ATP and NADPH to produce glucose.

When can the light independent reactions occur?

The light independent reactions can occur at all times, day and night.

What is cellular respiration?

Cellular respiration is a series of chemical reactions that occur in the mitochondria of cells to make energy available.

What are the two types of cellular respiration? -

Cellular respiration can be categorized into aerobic (with oxygen) and anaerobic (without oxygen).

What is the main function of aerobic cellular respiration?

Aerobic cellular respiration involves breaking down glucose in the presence of oxygen to release energy in the form of ATP, carbon dioxide, and water.

What are the three main stages of cellular respiration?

The three main stages are Glycolysis, Krebs Cycle, and Electron Transport System.

Where does glycolysis occur and what does it produce?

Glycolysis occurs in the cytoplasm and converts glucose into pyruvate.

What happens during the Krebs Cycle?

During the Krebs Cycle, pyruvate is converted into energy in the mitochondria.

Where is the largest amount of ATP produced in cellular respiration?

The largest amount of ATP is produced in the Electron Transport System in the mitochondria.

What is ATP?

ATP is a molecule that stores energy that cells make.

What is required for the successful occurrence of aerobic respiration? -

Aerobic respiration requires the presence of numerous enzymes.

What is the significance of the products from light dependent reactions in photosynthesis?

The products of light dependent reactions (ATP and NADPH) are required for the light independent reactions.

How do light dependent and light independent reactions relate to each other?

Light dependent and light independent reactions occur simultaneously, with products of the former being used in the latter.

What is produced as a byproduct of light dependent reactions?

Oxygen molecules are produced as a byproduct of light dependent reactions.