STEM Biology Grade 11 Term 3 Flashcards

Comprehensive vocabulary flashcards covering biological energy systems, cellular respiration, photosynthesis, and battery technology concepts from the Grade 11 STEM Biology curriculum.

Biology

The study of living organisms and how they interact at multiple levels to sustain life.

Domain

In the STEM curriculum nomenclature, this defines each STEM area, such as the Science Domain or Technology Domain.

Phylum

In the STEM curriculum nomenclature, this refers to what would normally be regarded as a subject, such as Biology, Physics, or Chemistry.

Energy

Defined as the ability to do work or the ability to cause some kind of change.

Kinetic Energy

The energy associated with an object's motion, such as a speeding bullet or a walking person.

Thermal Energy

The kinetic energy associated with the constant, random bouncing of atoms or molecules; its transfer between objects is known as heat.

Potential Energy

The energy associated with an object because of its position or structure, such as water held behind a dam.

Chemical Energy

A form of potential energy stored in the chemical bonds of a molecule related to the structure and positions of its atoms.

ATP (Adenosine Triphosphate)

The principle form of stored energy used for cellular functions, frequently referred to as the energy currency of the cell.

Neuron

The functional unit of the nervous system where electrical energy is transmitted along the axon.

Resting Potential

The electrical gradient across the cell membrane, generally measured at $-70\,mV$, maintained when a neuron is not actively transmitting an impulse.

Sodium-Potassium Pump

A mechanism of active transport that moves sodium ions out of cells and potassium ions into cells using energy from ATP to maintain resting potential.

Action Potential

Also called a nerve impulse, this is an electrical charge that travels along the membrane of a neuron when it is depolarized.

Threshold

The certain level of depolarization, generally about $15\,mV$ more positive than the resting potential, required to start an action potential.

Depolarization

The phase of an action potential where sodium ion channels open and the increase in positive charge inside the cell reaches about $+40\,mV$.

Repolarization

The phase where potassium ion channels open, allowing ions to flow out of the cell so the inside of the membrane becomes negative again.

Refractory Period

A brief period following an action potential during which another action potential cannot be generated.

Synapse

The place where an axon terminal meets another cell and transmission of a nerve impulse occurs.

Neurotransmitters

Chemicals used by most synapses to pass signals from the presynaptic cell to the postsynaptic cell.

Cellular Respiration

The process by which organisms convert large molecules like carbohydrates into smaller molecules like $CO_2$ and water to make energy available.

Catabolism

The process of breaking down large molecules to release small molecules and energy.

Anabolism

Metabolic processes that build larger molecules essential for survival, such as DNA and proteins.

Oxidation

The removal of an electron from a molecule, resulting in a decrease in the potential energy stored in the compound.

Reduction

The process of a compound accepting electrons, which increases its potential energy.

NAD+ (Nicotinamide Adenine Dinucleotide)

An electron carrier derived from vitamin $B_3$; its reduced form is NADH after accepting two electrons and a proton.

Glycolysis

The first step of cellular respiration occurring in the cytoplasm, breaking down one glucose molecule into two molecules of pyruvate.

Photosynthesis

The process used by plants to convert solar radiation into chemical energy in the form of sugar.

Calvin Cycle

Also known as the dark reactions or light-independent reactions, this process occurs in the stroma to produce glucose.

Photolysis

The splitting of water by light which releases protons ($H^+$), oxygen ions, and electrons.

Biomass

All plant, animal, and microbial matter originating through $CO_2$ fixation by photosynthesis.

Battery

A device that stores chemical energy and converts it to electrical energy via a chemical reaction involving the flow of electrons.

Anode

The negative terminal of a battery which contains an excess of electrons.

Cathode

The positive terminal of a battery which lacks electrons.

Primary Batteries

Non-rechargeable batteries intended for one-time use, such as those in watches or toys.

Secondary Batteries

Rechargeable batteries with electrochemical cells whose chemical reactions can be reversed by applying voltage, such as Lithium-Ion batteries.

Sino-atrial (SA) node

Also called the pacemaker, this group of excitatory cells at the top of the right atrium is responsible for initiating the heartbeat.

Electrocytes

Specialized cells in the electric eel lined up to allow a current of ions to flow, stacked to produce an electric potential difference.

Bio-battery

An electrical energy storage device powered by organic compounds like glucose and utilizing respiratory enzymes to generate electricity.

Thermoelectric Generators

Devices used in wearables to convert the body's internal temperature or natural heat into electricity.