VCE Biology - Unit 1, AOS 1

Plasma membrane

Separates the internal environment of a cell from the external environment. Also known as the cell membrane or phospholipid bilayer.

Nucleus

An organelle inside eukaryotic cells that contains the genetic material (DNA)

DNA

Contains the genetic information required to make all proteins for the cell. Stands for Deoxyribonucleic Acid.

Mitochondria

Organelle in which Cellular Respiration occurs. The site where the energy in glucose is converted to ATP. This organelle is known as the powerhouse of the cell.

Ribosome

Organelles which build proteins. This organelles role is link amino acids together, in a specific order, to form a polypeptide aka a protein.

Rough Endoplasmic Reticulum (RER)

An organelle, embedded with ribosomes, which synthesis proteins and transports them around the cell. Often found next to the nucleus

Golgi Body (Golgi Apparatus)

Processes and packages proteins produced by the RER into vesicles to be transported elsewhere.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs. Contains the pigment chlorophyll

Vacuole

A storage area. An organelle that stores materials such as water, salts, proteins, and carbohydrates within a cell.

Monomer

The building blocks of polymers.

Eg. Amino acids are the monomers of proteins.

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Eg. Proteins are polymers made up of chains of amino acids.

Biomacromolecules

Carbon-containing polymers in living systems commonly referred to as the molecules of life.

Carbohydrate

Organic molecules consisting of carbon, hydrogen and oxygen, usually in a ratio of C:H:O =1:2:1

Eg. Glucose C6 H12 06 (C:H:O = 6:12:6 = 1:2:1)

Protein

Large biomolecules (macromolecules) made up of long chains of amino acids.

Eg. Keratin is a protein in your hair and nails

Nucleic Acid

Large biomolecules (macromolecules) made up of nucleotides.

Eg. DNA and RNA are both nucleic acids

Lipid

Molecules that contain hydrocarbons and are insoluble in water. Includes fats, waxes, oils, phospholipids, and steroids.

Saccharide

Another name for sugar.

Monosaccharide

Aka carbohydrates, are simple sugars with C:H:O ratio of 1:2:1

Eg. Glucose, fructose, sucrose.

Amino Acid

The monomer that makes up a polypeptide and protein. Building block of proteins.

Nucleotide

The building blocks of DNA. Consists of a sugar, a phosphate and a nitrogenous base

Phospholipid

A class of lipids that are a major component in the cell membrane. The phosphate head is hydrophilic (water-loving) and 2 lipid tails is hydrophobic (water-hating).

Dissaccharide

Sugar formed when two monosaccharides are joined together.

Polysaccharide

A complex sugar, aka carbohydrate, made up of multiple saccharides (sugars).

Eg. Glycogen, starch, cellulose

Polypeptide

Another name for a long chain of amino acids. Also known as a protein

Glucose

The most common saccharide (simple sugar). Chemical formula C6H12O6.

Sucrose

A common saccharide found in plants and plant parts.

Lactose

A common disaccharide found in milk.

Fructose

A common monosaccharide found in fruit.

Starch

A complex carbohydrate (polysaccharide) consisting of multiple linked glucose units. It is the common form of energy storage in plants.

Glycogen

A complex carbohydrate (polysaccharide) that functions as energy storage in humans.

Cellulose

A polysaccharide which has an important role in the cell wall of plant cells. It provides the strength to the cell wall and is known as a structural carbohydrate, not an energy storage carbohydrate.

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Eukaryote

An organism composed of one or more cells containing a membrane‐bound nucleus and specialised organelles.

Unicellular

An organism that is composed of a single cell.

Multicellular

An organism that is composed of more than one cell.

Cell Wall

A rigid layer that surrounds the plasma membrane of plant, fungal and bacterial cells. It is made of cellulose in plants.

Enzyme

A protein that acts as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction.

Transport Protein

A protein embedded in the plasma membrane that helps a certain substance or class of closely related substances to cross the plasma membrane.

Catalyst

A substance that initiates or accelerates a chemical reaction without itself being affected

Catabolic

A process in which large molecules are broken down into simpler ones. For example, polymers being broken down to monomers (Eg. Proteins broken down into amino acid monomers)

Anabolic

A process in which simple molecules are built up into more complex ones. Eg. Proteins made by joining amino acids together

Active site

The part of an enzyme where a substrate attaches. The site is typically a pocket or groove on the enzyme's surface. The Site is complementary in shape to the substrate it binds to.

Substrate

A substance on which an enzyme acts during a chemical reaction. Binds to the active site of an enzyme, which is complementary in shape.

Product

A chemical substance formed as a result of a chemical reaction

Enzyme-Substrate Complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

Active Transport

The movement of a substance across a membrane AGAINST the concentration gradient with the help of energy input and specific transport proteins.

Passive Transport

Movement of substances across a cell membrane down a concentration gradient. Does not require energy. Includes diffusion, osmosis, and facilitated diffusion.

Intracelluar

Refers to within the cell

Extracellular

Refers to outside of the cell

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. A form of passive transport.

Osmosis

Diffusion of water molecules across a semipermeable membrane from an area of low solute concentration (high water concentration) to high solute concentration (low water concentration) until the concentration of solutes (and water) is equal on both sides of the membrane.

Facilitated Diffusion

A type of passive transport in which substances are transported across the plasma membrane through a channel protein (or carrier protein) down a concentration gradient, does not require the use of energy.

Hypertonic

A solution that has a higher concentration of solutes compared to another.

Hypotonic

A solution that has a lower concentration of solutes compared to another.

Isotonic

A solution whose solute concentration is equal to the solute concentration of another solution.

Concentration Gradient

A difference in the concentration of a solute across a distance.

Exocytosis

A form of active transport where a cell exports contents out of the cell.

Endocytosis

A form of active transport where a cell imports contents into the cell.

Photosynthesis

A process used by plants and other organisms to convert light energy into chemical energy. Process occurs in the chloroplast. A pigment called chlorophyll, found in chloroplasts, captures the light energy.

Word equation: Carbon dioxide + water = glucose and oxygen (in the presence of light)

Chemical equation: 6CO2 + 6H2O = C6H12O6 + 6O2

Cellular Respiration

A series of metabolic reactions and processes to convert glucose into adenosine triphosphate (ATP).

Word equation: glucose + oxygen = carbon dioxide + water

Chemical equation: C6H12O6 + 6O2 = 6CO2 + 6H2O

Surface Area:Volume ratio

Surface area of a shape divided by the volume of a shape. This ratio looks at the relationship between the needs of the cell and the capabilities of the cell (in terms of supplying nutrients to the cell)

>>A large SA:V ratio is more beneficial, allowing cells needs to be met efficiently. This is why cells are so small.

Autotroph

Organisms that are capable of producing their own food.

Eg. Plants

Heterotroph

An organism which must consume other organisms to obtain energy

Eg. Humans, carnivorous plants, animals

Organelle

A component of a cell that has a specific function. Examples include: mitochondria, Golgi apparatus, endoplasmic reticulum etc.

Glycolysis

Stage 1 of Cellular Respiration where glucose is converted into 2 pyruvates.

Input: Glucose

Output: Pyruvate

Kreb's Cycle

Stage 2 of Aerobic Respiration also known as Citric Acid Cycle. Pyruvate molecules are broken down to produce carbon dioxide.

Input: Pyruvate

Output: Carbon dioxide

Electron Transport Chain

Stage 3 of Aerobic Respiration. Electrons are transferred from donors to acceptors and protons are exchanged across the membrane creating a proton gradient which drives the synthesis of ATP.

ATP

Adenosine Triphosphate is an energy carrying molecule found in cells of all living things.