GCSE Combined Science: Trilogy - Biology, Chemistry, Physics Revision Flashcards

Flashcards covering key vocabulary for GCSE Combined Science: Trilogy, including Biology, Chemisty and Physics.

Light Microscope

An instrument using light to magnify images of cells and tiny objects, typically up to ×2000 magnification.

Electron Microscope

An instrument using electrons to magnify images up to 2 million times, revealing subcellular structures.

Magnification

The ratio of the size of an image to the size of the real object. Calculated as: magnification = size of image / size of real object

Scale Bar

A visual marker on microscope images indicating real sizes and enabling magnification calculation.

Resolving Power

The ability of a microscope to distinguish between two closely positioned objects.

Permanent Vacuole

A structure in plant and algal cells filled with cell sap, providing rigidity.

Cell Wall

A cellulose-based structure that strengthens plant and algal cells.

Chloroplasts

Organelles in plant and algal cells where photosynthesis occurs.

Cell Membrane

The outer boundary of a cell that controls the entry and exit of substances.

Nucleus

A large structure within cells containing genes that control cell activities.

Cytoplasm

The jelly-like substance filling a cell where many reactions occur.

Mitochondria

Tiny structures within cells where respiration takes place, releasing energy.

Ribosomes

Structures in the cytoplasm where proteins are made (protein synthesis).

Eukaryotic cells

Cells with a nucleus and other membrane-bound organelles, found in animals and plants.

Prokaryotic cells

Cells without a nucleus, such as bacteria; contain a cell wall, cytoplasm, and a loop of chromosomal DNA.

Magnification order

A power of ten. For example, something that is 10 times larger differs by one order of magnitude.

Ciliated Cells

Specialized animal cells with hair-like structures (cilia) that move substances past the cell surface.

Sperm Cells

Specialized animal cells that carry male genetic information, featuring a tail for movement and enzymes to penetrate egg cells.

Nerve Cells

Specialized animal cells that carry electrical impulses, featuring a long axon and dendrites for connections.

Muscle Cells

Specialized animal cells containing protein fibers for contraction, enabling movement.

Differentiation

The process by which cells specialize in structure and function during organism development.

Root Hair Cells

Specialized plant cells on root surfaces that absorb water and mineral ions.

Xylem Cells

Specialized plant cells forming transport tissue for water and mineral ions, reinforced with lignin.

Phloem Cells

Specialized plant cells that transport dissolved sugars throughout a plant, featuring sieve plates and companion cells.

Meristem Cells

Undifferentiated plant cells in root and shoot tips with the ability to differentiate throughout the plant's life.

Epidermal Tissue

Thin layer peeled from an onion to observe cells under a light microscope.

Mitosis

Cell division process that produces new identical body cells for growth, repair, and asexual reproduction.

Cell Cycle

The series of events involving interphase, mitosis, and cell division that leads to cell growth and division.

Parent Cell

The original cell that divides during mitosis.

Daughter cells

The two identical cells formed from the parent cell during mitosis.

Diploid cell

A cell that has two sets of chromosomes.

Stem Cells

Undifferentiated cells capable of producing more cells of the same type and differentiating into specialized cells.

Therapeutic Cloning

Producing an embryo with a patient's cell to generate stem cells for treating conditions like diabetes and paralysis.

Embryonic Stem Cells

Stem cells found in the early embryo, capable of differentiating into many different cell types.

Adult Stem Cells

Stem cells retained in adult animals, such as those in bone marrow that form blood cells.

Meristems

Plant tissues containing stem cells in root and shoot tips that differentiate throughout the plant’s life.

Diffusion

The spreading out of gas particles or substances in solution, resulting in net movement down a concentration gradient.

Concentration Gradient

The difference in concentration of a substance between two areas.

Exchange Surface

An area with adaptations to facilitate effective material exchange in multicellular organisms.

Surface Area to Volume Ratio

The relationship between a cell's surface area and its volume, affecting the efficiency of diffusion.

Villi

Finger-like structures in the small intestine lining that increase surface area for diffusion.

Osmosis

The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Partially Permeable Membrane

A membrane that allows small molecules (e.g., water) to pass through but not larger molecules (e.g., sucrose).

Active Transport

The movement of substances from a more dilute solution to a more concentrated solution, requiring energy from respiration.

Digestive Enzymes

Enzymes that convert larger food molecules into smaller, soluble molecules for absorption.

Carbohydrase

Enzymes that digest carbohydrates into simple sugars. For example Amylase: starch -> simple sugars

Protease

Enzymes that digest proteins into amino acids.

Lipase

Enzymes that digest lipids into fatty acids and glycerol.

Organ System

A group of organs working together in the body.

Chemical Analysis

The use of qualitive reagents to test for carbohydrates, lipids and proteins in foods.

Active site

The specific region of an enzyme where a substrate binds and reaction occurs.

Substrate

A molecule on which an enzyme acts.

Activation enzyme

The energy required to initiate a chemical reaction.

Enzymes: Effect of temperature

Enzymatic reaction rate increases with temperature to an optimum, beyond which denaturation occurs and rate decreases.

Enzymes: Effect of pH

Enzymes perform at optimum pH; deviating toward lower or higher levels results in denaturation.

Continuous Sampling

A method used to find the time taken to digest starch.

Buffer Solution

A mixture used to resists pH changes.

Rate of Reaction

Proportional to the time taken to finish the reaction; rate (/s) = 1 / time (s).

Plasma

The yellow liquid component of blood that transports cells, platelets, and dissolved substances.

Red Blood Cells

Cells in blood that transport oxygen using hemoglobin and lack a nucleus.

White Blood Cells

Part of the body's immune system with the ability to engulf and destroy pathogens.

Platelets

Blood fragments involved in forming blood clots at cuts or wounds.

Arteries

Blood vessels that carry blood away from the heart under high pressure.

Capillaries

Smallest blood vessels where substance exchange occurs between blood and surrounding cells.

Veins

Blood vessels that carry blood toward the heart under low pressure with valves to prevent backflow.