QCAA Year 11 Biology – Unit 1 Syllabus

Vocabulary flashcards covering Topic 1 (Cells as the basis of life), Topic 2 (Exchange of nutrients and wastes), and Topic 3 (Cellular energy, gas exchange and plant physiology) for QCAA Year 11 Biology Unit 1.

Prokaryotic Cell

A simple, single-celled organism that lacks a membrane-bound nucleus and other membrane-bound organelles.

Eukaryotic Cell

A complex cell containing a membrane-bound nucleus and specialized membrane-bound organelles.

Fluid Mosaic Model

A structural model describing the cell membrane as a dynamic phospholipid bilayer embedded with proteins, cholesterol, and glycoproteins.

Totipotent Stem Cells

Stem cells that have the potential to differentiate into any cell type, including both embryonic and extraembryonic tissues.

Pluripotent Stem Cells

Stem cells capable of giving rise to almost all cell types of the body, but not extraembryonic tissues.

Multipotent Stem Cells

Stem cells that can develop into a limited number of specialized cell types within a specific tissue or organ.

Unipotent Stem Cells

Stem cells capable of differentiating into only one specific cell type, while maintaining self-renewal properties.

Surface-Area-to-Volume Ratio

The relationship between a cell's outer surface area and its internal volume, which constrains cell size and dictates the rate of diffusion.

Principles of Replacement, Reduction, and Refinement

Ethical guidelines in animal research prioritizing non-animal alternatives (replacement), fewer animals (reduction), and minimized distress (refinement).

Amylase

A digestive enzyme that catalyzes the breakdown of carbohydrates into simpler sugar molecules.

Protease

A digestive enzyme that hydrolyzes proteins into peptides and amino acids.

Lipase

A digestive enzyme that breaks down lipids into fatty acids and glycerol.

Intestinal Villi

Finger-like projections lining the small intestine that increase surface area to maximize the rate of nutrient absorption into capillaries.

Glomerular Filtration

The passive process in the kidney where blood pressure forces water and small solutes from the glomerulus into Bowman's capsule.

Selective Reabsorption

The process along the nephron tubule where essential substances like glucose, ions, and water are reclaimed back into peritubular capillaries.

Nephron Secretion

The active movement of excess ions, metabolic wastes, and drugs from capillary blood directly into the nephron filtrate.

Induced-Fit Model

An enzyme action model proposing that an enzyme's active site undergoes a conformational change upon substrate binding to optimize catalysis.

Enzyme Inhibitors

Chemical substances that bind to enzymes and decrease or prevent their catalytic activity.

Catabolism

Metabolic pathways that break down complex molecules into simpler ones, releasing energy.

Anabolism

Metabolic pathways that construct complex molecules from simpler building blocks, requiring an input of energy.

Adenosine Triphosphate (ATP)

The universal energy currency of cells that transfers energy released by catabolic reactions to drive anabolic processes.

Glycolysis

The initial step of cellular respiration occurring in the cytoplasm, breaking down glucose into pyruvate with a net gain of ATP.

Krebs Cycle

A series of aerobic reactions in the mitochondrial matrix that oxidize pyruvate derivatives, producing $CO_2$, ATP, and high-energy electron carriers.

Electron Transport Chain

A chain of protein complexes located in the inner mitochondrial membrane that uses electron transfers to generate the majority of cellular ATP.

Alveoli

Microscopic, thin-walled air sacs in mammalian lungs that provide a large surface area for efficient gas exchange with adjacent capillaries.

Light-Dependent Reactions

The initial reactions of photosynthesis in the thylakoid membranes that capture light energy and split water to produce ATP, NADPH, and $O_2$.

Light-Independent Reactions

The stage of photosynthesis occurring in the chloroplast stroma where ATP and NADPH are used to fix carbon dioxide into glucose.

Xylem

Vascular tissue in plants responsible for transporting water and dissolved mineral ions upward from the roots to the shoots.

Phloem

Vascular tissue in plants responsible for translocating sugars and other organic nutrients throughout the plant.

Transpiration

The evaporative loss of water vapor from aerial plant surfaces, primarily occurring through stomatal pores.

Guard Cells

Specialized epidermal cells that flank stomatal pores and regulate gas exchange and transpiration by altering their turgor pressure.

Artificial Leaves

Biomimetic technology designed to convert solar energy, water, and carbon dioxide directly into liquid fuel.