Grade 10 Life Sciences: Chemistry of Life, Cells, and Mitosis

Comprehensive vocabulary flashcards covering basic biological chemistry, cell structure, microscopy, transport mechanisms, mitosis, and cancer from Grade 10 Life Sciences.

Water

The most important inorganic compound for living organisms, composed of two hydrogen atoms and one oxygen atom ($H_2O$); serves as a solvent, reaction medium, transport agent, lubricant, temperature regulator, and provides shape and rigidity.

Mineral salts

Inorganic substances or elements needed and absorbed by living organisms from soil (by plants) or food (by animals), divided into macro-elements and micro-elements.

Macro-elements

Mineral salts needed by living organisms in large quantities, such as calcium (Ca), phosphorus (P), sodium (Na), and potassium (K).

Micro-elements

Mineral salts needed by living organisms in small quantities, such as iron (Fe) and iodine (I).

Calcium (Ca)

A macro-element that builds strong bones and teeth, enables blood coagulation, regulates cell membrane permeability, muscle contraction, and nerve impulses; deficiency causes rickets, osteomalacia, and osteoporosis in humans, and weak root growth in plants.

Phosphorus (P)

A macro-element that builds strong bones and teeth and serves as a component of ATP, DNA, RNA, and phospholipids; deficiency causes stunted plant growth.

Sodium (Na)

A macro-element important for maintaining water balance in the body, nerve functioning, muscle contraction, and controlling heart rhythm; deficiency causes muscle cramps in humans.

Potassium (K)

A macro-element maintaining water balance, muscle and nerve functioning, heart rhythm regulation, and plant enzyme activation; deficiency causes yellow and brown leaf margins in plants.

Iron (Fe)

A micro-element required to form haemoglobin that transports oxygen in the blood and chlorophyll in plants; deficiency causes anaemia in humans and chlorosis in plants.

Iodine (I)

A micro-element component of the hormone thyroxin secreted by the thyroid gland; deficiency causes goitre (swelling of the neck or larynx) in humans.

Carbohydrates

Organic compounds composed of carbon (C), hydrogen (H), and oxygen (O) with a ratio of H atoms to O atoms of $2:1$, made up of ring-shaped units called saccharides.

Monosaccharides

Single-ring carbohydrate monomers that are sweet and water-soluble; includes glucose, fructose, and galactose.

Disaccharides

Double sugars formed by joining two monosaccharides through a condensation reaction with the removal of one $H_2O$ molecule; includes maltose, sucrose, and lactose.

Condensation reaction

A chemical reaction in which two molecules join together with the removal of one molecule of water ($H_2O$).

Polysaccharide

Long chains of monosaccharides joined by condensation reactions; insoluble and non-sweet, including starch (plant energy storage), glycogen (animal glucose storage in liver and muscle), and cellulose (plant cell walls).

Lipids (fats and oils)

Organic molecules composed of C, H, and O with an H to O ratio far greater than $2:1$, formed from 1 glycerol and 3 fatty acids; insoluble in water, soluble in ether and alcohol, and hydrophobic.

Saturated fats

Fats mainly derived from animals (e.g., butter, lard) that are solid at room temperature; excessive intake increases cholesterol, leading to fatty deposits in arteries.

Atherosclerosis

The narrowing of arteries due to fatty deposits (plaque) caused by high blood cholesterol levels, which can lead to blood clots and heart attacks.

Unsaturated fats

Fats mainly derived from plants (e.g., olive oil, canola oil, sunflower oil) that are liquid at room temperature and commonly known as oils.

Proteins

Polymers made of amino acid monomers linked by peptide bonds, composed of C, H, O, N, and sometimes P, S, and Fe; essential for structure, hormones, enzymes, antibodies, and transport.

Peptide bond

The chemical link or bond formed between two amino acids.

Denature

The process whereby a protein permanently loses its shape and can no longer perform its function, caused by high temperature or extreme pH.

Enzymes

Biological catalysts that accelerate chemical reactions without being changed by the reaction; they are substrate-specific proteins.

Hydrolysis

A catabolic digestive reaction in which complex molecules are broken down into simple soluble molecules by the addition of water, catalysed by enzymes.

Substrate

The specific substance on which an enzyme acts during a chemical reaction.

Nucleic acids

Organic compounds containing C, H, O, N, and P; occurs as DNA (carries hereditary information in chromosomes) and RNA (functions in protein synthesis).

Water-soluble vitamins

Vitamins B and C, which are absorbed together with water, cannot be stored in the body, and are excreted in urine, requiring regular intake.

Fat-soluble vitamins

Vitamins A, D, E, and K, which can only be absorbed when dissolved in fat and are stored in the body.

Cell theory

A biological theory formulated in 1839 by Theodore Schwann, Mathias Schleiden, and Rudolf Virchow stating that all living organisms are made up of cells, the cell is the basic and smallest unit of life, and all cells originate from existing cells.

Antonie van Leeuwenhoek

The Dutchman who built a simple single-lens microscope in 1674, described bacteria for the first time, and is regarded as the father of microscopy.

Parts of a light microscope

The mechanical and optical components of an optical microscope, including the eyepiece, objective lenses, stage, condenser, iris diaphragm, light source, arm, and adjustment knobs.

Prokaryotic cell

A cell that lacks a membrane-bound nucleus, such as a bacterium.

Eukaryotic cell

A cell that contains a distinct membrane-bound nucleus.

Differentiation

The process by which cells change their size, shape, and structure in order to perform specific functions.

Protoplasm

The living material within plant and animal cells, consisting of the cytoplasm and nucleus.

Primary cell wall

A thin outer layer found in all plant cells outside the cell membrane, consisting mainly of stretchable cellulose fibres.

Middle lamella

A layer consisting of pectin that occurs outside the primary cell wall and connects the cell walls of adjacent plant cells.

Secondary cell wall

An inelastic layer composed of thick cellulose fibres that develops between the cell membrane and the primary cell wall as plant cells mature.

Cyclosis

The streaming circulation of substances caused by the movement of the cytoplasm within a living cell.

Fluid Mosaic Model

The structural representation of the selectively permeable cell membrane, depicting a double layer of phospholipids with embedded protein molecules.

Diffusion

The spontaneous movement of molecules of a liquid or gas from an area of high concentration to an area of low concentration until equilibrium is reached.

Osmosis

The movement of water molecules from an area of high water potential to an area of low water potential through a selectively permeable membrane until equilibrium is reached.

Active transport

The movement of molecules from a low concentration to a high concentration through membranes against the concentration gradient, requiring cellular energy.

Passive transport

The movement of molecules from high to low concentration driven solely by their kinetic energy without requiring energy expenditure.

Mitochondrion

A cylindrical hollow-rod organelle enclosed by a double membrane with cristae and matrix, known as the 'power house' of the cell where cellular respiration produces ATP.

Ribosome

An organelle consisting of RNA and proteins located in the ER, mitochondria, chloroplasts, or freely in cytoplasm (polyribosomes), serving as the site of protein synthesis.

Endoplasmic reticulum (ER)

A network of internal membranes that transports substances and increases surface area; classified as Rough ER (bearing ribosomes) or Smooth ER (lacking ribosomes).

Golgi body

An organelle consisting of cisternae and vesicles located near the nucleus in cells with a secretory function.

Structure of a plant cell

The anatomical organization of a plant cell featuring a cell wall, large central vacuole with tonoplast, chloroplasts, cytoplasm, and nucleus.

Structure of an animal cell

The anatomical organization of an animal cell characterized by the absence of a cell wall and chloroplasts, and the presence of lysosomes and centrosomes.

Mitosis

The division of somatic (body) cells resulting in two genetically identical daughter cells identical to the mother cell, functioning in growth, repair, and asexual reproduction.

Replication

The biological process occurring prior to cell division in which an exact, identical copy of nuclear DNA is made.

The Cell Cycle

The complete period during which a cell grows, replicates genetic material, and divides, comprising Interphase and Mitosis.

Karyokinesis

The stage of cell division involving the division of the nucleus and chromosomes.

Cytokinesis

The stage of cell division involving the division of the cytoplasm, organelles, and cell membrane.

Prophase

The first phase of mitosis where chromatin condenses into visible double-stranded chromosomes, the nuclear membrane and nucleolus disappear, and spindle fibres form between separating centrioles.

Metaphase

The mitotic phase where double-stranded chromosomes align in a single row along the equator of the cell and attach to spindle fibres by their centromeres.

Anaphase

The mitotic phase where centromeres divide, sister chromatids separate into daughter chromosomes moving to opposite poles, and cytokinesis begins.

Telophase

The final phase of mitosis where daughter chromosomes uncoil, nuclear membranes and nucleoli reform around two identical daughter nuclei, and cytokinesis is completed.

Cancer

A condition resulting from uncontrolled mitotic cell division in the body, forming non-functional groups of cells that develop into a tumour.

Benign tumour

A tumour enclosed within a capsule that does not penetrate or invade surrounding tissues.

Malignant tumour

A tumour that spreads between and infiltrates the cells of surrounding tissues, causing damage.

Carcinogen

Any agent capable of causing cancer, such as cigarette smoke, sun, asbestos, radiation (x-rays), pollutants, or hormonal imbalances.

Chemotherapy

The use of chemical agents or drugs to destroy cancer cells.

Radiotherapy

The medical use of radioactive radiation to destroy cancer cells.