Year 11 Biology - Module 1: Cells as the Basic Units of Life

Vocabulary practice flashcards generated from Year 11 Biology notes on cell structures, membrane transport, enzymes, photosynthesis, cellular respiration, and scientific methodologies.

Accuracy

The degree to which a measurement, calculation, or specification conforms to the true, accepted, or target value.

Validity

The soundness and logical strength of a measure, argument, or claim, indicating how well it reflects real-world truth or the intended concept.

Reliability

The consistency, dependability, and trustworthiness of a measure, ensuring it produces similar, accurate results under consistent conditions over time.

Prokaryotic Cell

A simple, single-celled microorganism (specifically bacteria and archaea) that lacks a membrane-bound nucleus and specialised organelles.

Eukaryotic Cell

A complex cell type characterized by having its genetic material ($DNA$) enclosed within a distinct membrane-bound nucleus and possessing various membrane-bound organelles.

Bacteria

Tiny, single-celled, prokaryotic microorganisms lacking a nuclear membrane, found throughout Earth's ecosystems and in or on the human body.

Archaea

A distinct domain of single-celled, prokaryotic microorganisms that lack a nucleus, possess unique cell membrane lipids, and are structurally similar to bacteria but genetically closer to eukaryotes.

Organelle

A membrane-bound structure within a eukaryotic cell that performs a specialised function.

Nucleus

A large organelle bounded by a double membrane that contains most of the cell's $DNA$ and controls cell activities by determining protein synthesis.

Ribosomes

Non-membrane-bound structures consisting of two subunits that function as the site of protein synthesis in both prokaryotes and eukaryotes.

Endoplasmic Reticulum

Networks of membrane-bound sacs acting as transport pathways in the cell, existing as Rough ER (transports proteins) and Smooth ER (transports other compounds like lipids).

Mitochondria

Double-membrane-bound organelles with a smooth outer layer and a rippled inner layer that serve as the site of aerobic cellular respiration.

Golgi Apparatus

A stack of flattened sacs that bud off into vesicles, functioning to modify proteins and package them for export from the cell.

Centriole

A non-membrane-bound structure in fungal and animal cells that organises spindle fibres during cell division.

Chloroplasts

Large double-membrane organelles containing thylakoids and chlorophyll that act as the site of photosynthesis.

Lipids

Macromolecules made up of fatty acid monomers that are nonpolar and hydrophobic, functioning in energy storage, membrane structure, and insulation.

Triglycerides

A main form of stored energy in animals and plants composed of one glycerol molecule bonded to three fatty acids.

Phospholipids

Amphipathic lipids featuring a hydrophilic, phosphate-containing head and two hydrophobic fatty acid tails, forming cell membranes.

Proteins

Large, complex biomolecules composed of amino acid chains linked by peptide bonds, functioning as structural components, enzymes, and cell regulators.

Amino Acids

Organic compounds containing amine ($-NH_2$) and carboxyl ($-COOH$) functional groups that serve as the building blocks of proteins.

Carbohydrates

Compounds made of carbon, hydrogen, and oxygen that are broken down into glucose to provide energy for cells.

Selectively Permeable

The property of the cell membrane that controls the exchange of material by allowing only certain molecules or ions to pass in or out.

Cytoplasm

The jellylike substance filling the interior of a cell enclosed by the membrane, consisting of water, salts, and nutrients.

Solute

A solid, liquid, or gas substance that dissolves in a solvent to form a solution.

Solvent

A substance (most commonly water) that dissolves solutes to form solutions.

Solution

A homogeneous mixture in which a solute is uniformly dissolved in a solvent.

Diffusion

The passive movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached.

Concentration Gradient

The difference in particle concentration between two points; a greater difference produces a faster rate of diffusion.

Equilibrium

A balanced state where concentration is equal on both sides of a membrane and no net change occurs.

Dynamic Equilibrium

A balanced state where substances are equal in concentration on both sides, but particles continue to move or change.

Simple Diffusion

The passive movement of small molecules (such as $O_2$ or $CO_2$) directly across the cell membrane from high to low concentration.

Facilitated Diffusion (Channel Proteins)

Passive transport of larger or charged molecules (such as glucose or ions) across the membrane using channel proteins that act like tunnels.

Facilitated Diffusion (Carrier Proteins)

Passive transport of molecules across the cell membrane using carrier proteins that change shape to carry the molecule through.

Integral Proteins

Proteins embedded inside the cell membrane that can extend all the way through to transport substances and facilitate cell communication.

Peripheral Proteins

Proteins located on the inner or outer surface of the cell membrane that assist with cell shape, support, and attachment.

Receptor Proteins

Membrane proteins that act like locks to allow the cell to respond to specific external chemical signals.

Marker Proteins

Membrane proteins that function as ID tags to help the immune system recognise its own cells.

Cholesterol

A lipid molecule in the cell membrane that regulates fluidity and maintains stability across changing temperatures.

Osmosis

The movement of water through a membrane from an area with less water to an area with more water until balanced on both sides.

Photosynthesis

The process in chloroplasts where plants use light energy, water, and carbon dioxide to form glucose and oxygen ($6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$).

Cellular Respiration

The process in mitochondria where cells break down glucose and oxygen to release energy stored in $ATP$ ($C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$).

Reciprocal Reaction

A pair of chemical processes in which the products of one reaction serve as the reactants for the other reaction.

Enzymes

Globular protein molecules that act as biological catalysts, increasing reaction rates by lowering activation energy without being consumed.

Activation Energy

The minimum energy required for a chemical reaction to occur, allowing reactants to reach the transition state.

Metabolism

The sum of all chemical reactions occurring within a living organism to maintain life.

Anabolic Reactions

Metabolic synthesis reactions that build up larger, complex molecules from smaller ones.

Catabolic Reactions

Metabolic decomposition reactions that break down larger molecules into smaller particles.

Denaturation

The loss of an enzyme's structural shape and functionality due to adverse environmental conditions such as overheating.

Lock and Key Model

An enzyme mechanism model stating that the active site of an enzyme is a precise, rigid match for a specific substrate.

Induced Fit Model

An enzyme mechanism model stating that the active site is flexible and adjusts shape upon substrate binding for a tighter fit.

Cofactor

A substance other than the substrate that fits into the active site and is necessary for enzyme activity.

Coenzyme

An organic cofactor that is altered during an enzymatic reaction and must be replenished before subsequent reactions.

Competitive Inhibitor

A substance that directly binds to the active site of an enzyme, preventing substrate entry.

Non-competitive Inhibitor

A substance that binds to an allosteric site on an enzyme, changing the active site shape so the substrate no longer fits.

Active Transport

The movement of substances across a cell membrane against the concentration gradient (from low to high concentration) using transport proteins and energy ($ATP$).

Unicellular Organism

An organism composed of a single cell where all necessary life processes are carried out at the cellular and organelle levels.

Colonial Organism

A group of individual unicellular organisms living in contact with one another without cell specialisation.

Multicellular Organism

An organism composed of many interdependent cells displaying cellular specialisation and division of labour.

Enzyme-Substrate Complex

The intermediate structure formed when an enzyme ('A') binds specifically with a substrate ('B') at its active site before releasing the products.

Experimental Evaluation Criteria

The key requirements for scientific testing: Accuracy (proper equipment use), Reliability (repeatable consistent results), and Validity (controlled variables).

Passive Transport Pathways

Movement of materials across membranes without energy input, branching into simple diffusion and facilitated diffusion.

Active Transport Pathways

Energy-requiring movement of materials across membranes using transport proteins & $ATP$, or vesicular methods like endocytosis and exocytosis.