Updated BIO FULL YEAR FLASHCARDS

Atom

Basic building block of all matter.

Molecule

A group of atoms chemically bonded together.

Organic Molecule

Any molecule containing a carbon (C) atom. Life as we know it is carbon

Macromolecule

A large organic molecule made up of smaller molecules; made up of a large number of atoms. There are four major types that make up all living things: carbohydrates, lipids, proteins, and nucleic acids.

Polymer

Long chains built from smaller, repeating units called monomers. Macromolecules are often referred to as polymers.

Monomer

The smaller, repeating units that are the building blocks of polymers.

Dehydration Synthesis

The chemical process of building large polymers from smaller monomers. During this process, a molecule of water is removed for each monomer added to the growing chain.

Hydrolysis

The chemical process of breaking down polymers back into their individual monomers. This involves adding a molecule of water to break the bonds.

Carbohydrates

Molecules composed of carbon (C), hydrogen (H), and oxygen (O) atoms, also known as sugars or starches. Their primary roles are to provide a quick source of energy and to serve as structural components.

Monosaccharide

The monomer (basic building block) of carbohydrates. Glucose is a common example.

Disaccharide

A sugar formed when two monosaccharides join together.

Polysaccharide

A carbohydrate composed of many monosaccharides linked together. Examples include starch (energy storage in plants) and cellulose (structural component in plant cell walls).

Lipids

A group of macromolecules made primarily of carbon (C), hydrogen (H), and oxygen (O) atoms, though their structure is different from carbohydrates. Common types include fats, oils, and waxes.

Lipid Functions

Long term energy storage (storing more energy per gram than carbohydrates), forming structural components (like cell membranes), providing insulation and protection for organs, and serving as precursors for hormone production.

Glycerol & Fatty Acids

The monomers of lipids.

Triglyceride

A common type of lipid consisting of one glycerol molecule linked to three fatty acid chains.

Phospholipids

Lipids with a phosphate group attached. They are key components of cell membranes.

Waxes

Long chain lipids that are insoluble in water and provide protective coatings.

Proteins

Highly diverse and complex macromolecules composed of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sometimes sulfur (S) atoms. They are involved in almost every biological process.

Protein Functions

Providing structural support (e.g., hair, nails, muscle), enabling movement (e.g., muscle contraction), facilitating chemical reactions (as enzymes), transporting substances, signaling, and defending the body.

Amino Acids

The monomers of proteins. There are 20 different types, and their specific sequence determines a protein's unique structure and function.

Peptide Bond

A special type of covalent bond that joins amino acids together.

Polypeptide

A chain of many amino acids linked by peptide bonds. It folds into a specific three

Denaturation

The process where a protein loses its specific three

Enzyme

A particularly important class of proteins that act as biological catalysts. They speed up chemical reactions in living organisms without being consumed. Their shape is crucial for function and they can be reused many times.

Catalyst

Something that increases the rate of a chemical reaction without itself undergoing chemical change.

Active Site

The specific region on an enzyme where it binds to specific molecules called substrates. It has a unique shape that fits the substrate, like a lock and key.

Nucleic Acids

Macromolecules composed of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) atoms. Their most critical function is to store and transmit genetic information.

Nucleotide

The monomer of nucleic acids. Each nucleotide consists of three parts: a sugar, a phosphate group, and a nitrogenous base.

DNA (Deoxyribonucleic Acid)

Typically a double stranded polymer, forming a twisted ladder shape known as a double helix. Its primary function is to store the complete genetic blueprint for an organism.

RNA (Ribonucleic Acid)

Typically a single stranded polymer. Its main function is to code for the production of proteins, acting as a messenger and helper in translating genetic information from DNA into functional proteins.

Cell

The basic unit of life. It is the smallest entity that scientists regard as living and is the fundamental feature distinguishing all forms of life from non

Organelle

Specialized parts within a cell that work together to perform specific jobs vital for the cell's survival and function. The word means "tiny organ".

Cytoplasm

The internal environment within the cell membrane, mostly water, where all the organelles are suspended.

Cell Membrane

A thin, flexible barrier that encloses and protects the cell, maintaining its internal environment. It carefully controls what enters and leaves the cell, acting as a selective filter.

Phospholipid Bilayer

The primary composition of the cell membrane, a double layered sheet of phospholipid molecules.

Phospholipid

A molecule with a hydrophilic (water loving) phosphate "head" (polar) and two hydrophobic (water fearing) lipid "tails" (nonpolar). This dual nature (amphiphilic) causes them to arrange into a stable bilayer in watery environments, with heads facing outwards and tails inwards.

Fluid Mosaic Model

The dynamic description of the cell membrane. It's a "mosaic" because it's made of various molecules (phospholipids, carbohydrates, proteins, cholesterol). It's "fluid" because these molecules are constantly moving and flowing, giving the membrane flexibility.

Semi permeable (or Selectively Permeable) Membrane

A property of the cell membrane meaning it allows some substances to pass through while blocking others. Generally, small, nonpolar, fat soluble molecules diffuse directly, while larger, polar molecules and ions require special transport mechanisms.

Membrane Proteins

Embedded in the cell membrane, they act like gates, allow cells to recognize each other and communicate, and protect cells from infections.

Nucleus

Often considered the "control center" of the cell. It's a large organelle enclosed by a double membrane (nuclear envelope) and contains the cell's genetic information (DNA), which is like the blueprint for cell activities.

Nucleolus

Located inside the nucleus, its primary job is to make ribosomes.

Ribosomes

Tiny structures responsible for making proteins. They can float freely in the cytoplasm or be attached to the endoplasmic reticulum.

Endoplasmic Reticulum (ER)

A vast network of flattened membrane sacs connected to the nuclear membrane. It is a site for the synthesis and transport of many cell products.

Rough ER

Has ribosomes attached, involved in the synthesis and folding of proteins destined for secretion or membrane insertion.

Smooth ER

Lacks ribosomes, involved in synthesizing lipids (fats and oils), detoxifying drugs/poisons, and storing calcium ions.

Golgi Apparatus (or Golgi Complex/Body)

A stack of flattened membrane

Cell Wall

(Found in plant cells, fungi, and some prokaryotes, but not animal cells). This rigid outer layer provides protection and structural support to the cell and connects adjacent cells. In plants, it is primarily made of cellulose.

Chloroplasts

(Found in plant cells and some protists). These are the sites of photosynthesis, containing the green pigment chlorophyll.

Cytoskeleton

An intricate network of protein fibers (microtubules and filaments) throughout the cytoplasm. It provides structural support, helps maintain cell shape, and serves as tracks for organelle movement.

Lysosomes

(More common in animal cells). Sac like organelles containing powerful digestive enzymes that break down waste materials, cellular debris, and foreign invaders. They are sometimes called "suicide sacs".

Mitochondria

Often called the "power plants" of the cell. They are responsible for converting high

Centrioles

(Found in animal cells). Small, cylindrical organelles involved in cell division, helping to organize microtubules.

Vacuoles

Membrane bound sacs that serve as storage bins for water, nutrients, and waste products. In plant cells, a large central vacuole helps maintain turgor pressure.

Eukaryotes

Cells that contain a nucleus. They are typically larger (between 10µm and 100µm).

Prokaryotes

Cells that do not contain a nucleus. They are typically smaller (between 1µm and 10µm).

Particle Model of Matter

All matter is made up of tiny particles (atoms or molecules) that are in constant, random motion.

Brownian Motion

The constant, random motion of particles.

Concentration Gradient

The difference in concentration between two areas. Molecules naturally move down a concentration gradient (from high concentration to low concentration).

Equilibrium

The state reached when molecules are evenly distributed throughout an area. Particles still move, but there is no net change in their distribution.

Passive Transport

The movement of molecules across the cell membrane that does not require any energy or effort from the cell. It relies on molecules moving down their concentration gradient.

Diffusion

The natural movement of particles from an area of high concentration to an area of low concentration. For cells, this happens directly across the lipid bilayer for small, nonpolar, fat soluble molecules like oxygen and carbon dioxide.

Facilitated Diffusion

A type of diffusion that uses transport proteins (like channel or carrier proteins) embedded in the cell membrane to help larger or polar molecules cross. These molecules still move down their concentration gradient, so no extra energy is required.

Osmosis

The diffusion of water through a semi permeable membrane. Water moves from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) to equalize solute concentrations.

Hypertonic Solution

A solution where the concentration of solutes outside the cell is greater than inside. Water flows out of the cell, causing it to shrink.

Isotonic Solution

A solution where the concentration of solutes inside and outside the cell are equal. There is no net water movement, and cell shape remains unchanged.

Hypotonic Solution

A solution where the concentration of solutes outside the cell is lower than inside. Water flows into the cell, causing it to swell (and potentially burst if an animal cell).

Active Transport

The process where a cell moves molecules against their concentration gradient (from low to high concentration). This process requires energy.

ATP (Adenosine Triphosphate)

Considered the cell's primary energy currency. It is primarily produced in the mitochondria.

Transport Proteins (Pumps)

Specific proteins embedded in the membrane that act like "pumps," binding to molecules and using ATP energy to move them across the membrane.

Bulk Transport

Processes used for moving very large particles, or a large amount of small particles, involving changes in the cell membrane itself. These processes are generally energy

Endocytosis

The process where the cell membrane folds around an object, pinches it off, and releases the pinched

Phagocytosis

A type of endocytosis known as "cell eating," where the cell engulfs large solid particles, such as bacteria or cellular debris.

Pinocytosis

A type of endocytosis known as "cell drinking," where the cell takes in fluid droplets and dissolved solutes from the outside environment.

Exocytosis

The reverse of endocytosis. A vesicle containing material moves to the cell membrane, fuses with it, and releases its contents into the external environment, allowing the cell to rid itself of waste or send new products outside.

Surface Area to Volume (SA/V) Ratio

A critical factor in the efficiency of cell transport and overall cellular function.

Importance of Large SA/V Ratio

A large surface area relative to volume means the distance from any point within the cell to the cell membrane is very small, allowing molecules to move quickly. More surface area also provides more contact with the external environment, facilitating efficient exchange of nutrients and wastes. This is why cells are typically small.

Cell Size Limitation

Diffusion over long distances within the cytoplasm of a single large cell would be slow and inefficient, making many small cells more advantageous than one large cell.

Root Hairs

Tiny projections from single root cells that greatly increase the surface area of the root, maximizing the absorption of water and minerals from the soil.

Xylem Sap

A solution of water and dissolved minerals that accumulates in the xylem after absorption by root cells.

Vascular System (Plants)

A highly organized system for long

Xylem Vessels

The primary transporters of water and dissolved minerals from the roots upwards to the rest of the plant. Most xylem cells are dead at maturity, forming hollow tubes of cell walls linked end to end.

Phloem Vessels

Transport sucrose (sugar), produced during photosynthesis in the leaves, to other parts of the plant where it's needed for energy or storage. Most phloem cells are living.

Root Pressure

A force for water movement in plants where minerals are actively transported into root xylem, and water follows by osmosis, creating a build

Transpirational Pull (Cohesion Tension Theory)

The main driving force for water movement in tall plants. As water evaporates from leaves, it creates a negative pressure (tension) that pulls the water column upwards.

Transpiration

The process by which plants lose water vapor from their leaves, primarily through stomata.

Cohesion

The attraction of water molecules to other water molecules (due to hydrogen bonds), allowing water to stick together and form a continuous column from roots to leaves.

Adhesion

The attraction of water molecules to other surfaces, like the walls of xylem vessels, helping to prevent the water column from breaking.

Leaves

The primary sites of photosynthesis and gas exchange in most plants.

Epidermis (Leaf)

The outermost protective layer of cells covering the leaf, typically clear and lacking chloroplasts to allow light to pass through.

Cuticle (Leaf)

A waxy layer secreted by the epidermis that helps prevent excessive water evaporation from the leaf surface. It is not made of cells.

Palisade Cells

Long, narrow columns of cells located just beneath the upper epidermis, tightly packed with chloroplasts. This is where the majority of photosynthesis occurs.

Spongy Tissue

Located below the palisade layer, these cells are irregularly shaped with many air spaces between them. These spaces allow gases (CO₂, O₂, water vapor) to move and be exchanged efficiently. Some photosynthesis also occurs here.

Stomata (singular: stoma)

Tiny pores or gaps, mostly found on the underside of leaves, that provide an opening for gas exchange between the plant's interior and the atmosphere.

Guard Cells

Two specialized cells that flank each stoma. They swell or shrink to open or close the stomata, regulating gas exchange and water loss.

Lenticels

Small, raised pores that perforate the bark on stems and roots in woody plants, allowing for gas exchange in parts of the plant without leaves.

Photosynthesis

The process by which plants (and some other organisms) convert light energy into chemical energy, producing glucose (sugar) and oxygen from carbon dioxide and water.

Photosynthesis Equation

6CO₂ + 6H₂O + sunlight energy → C₆H₁₂O₆ + 6O₂.

Chlorophyll

The green colored pigment found in plants that absorbs photons (packets of light energy) from the sun, initiating photosynthesis.

Chlorophyll a

The primary light absorbing pigment; the only one that can directly transfer solar energy to photosynthesis reactions.