Studying For HRS BIO Exam

Organic compounds

Carbon-containing molecules found in living organisms

Polymers

Large molecules composed of repeating subunits called monomers

Monomers

Small molecular units that combine to form polymers

Dehydration reactions

Chemical reactions that join monomers by removing water

Hydrolysis reactions

Chemical reactions that break down polymers by adding water

Carbohydrates

Organic compounds composed of carbon, hydrogen, and oxygen, serving as energy sources and structural components

Lipids

Hydrophobic organic molecules that include fats, oils, and steroids

Proteins

Large, complex molecules made up of amino acids, performing various functions in organisms

Nucleic acids

Macromolecules that store and transmit genetic information (DNA and RNA)

Fatty acids

Long hydrocarbon chains with a carboxyl group, components of lipids

Amino acids

Organic compounds containing an amino group and a carboxyl group, building blocks of proteins

Nucleotides

Subunits of nucleic acids, consisting of a sugar, phosphate group, and nitrogenous base

Peptide bonds

Chemical bonds that link amino acids in proteins

Polypeptides

Chains of amino acids joined by peptide bonds

Saccharides

Another term for carbohydrates

Monosaccharides

Simple sugars, such as glucose and fructose

Disaccharides

Carbohydrates composed of two monosaccharides, like sucrose

Polysaccharides

Complex carbohydrates made up of many monosaccharides, such as starch and cellulose

Glucose

A simple sugar and primary energy source for cells

Fructose

A monosaccharide found in fruits and honey

Sucrose

A disaccharide composed of glucose and fructose

Amylose

A type of starch molecule with a linear structure

Starch

A polysaccharide used for energy storage in plants

Cellulose

A structural polysaccharide found in plant cell walls

Nitrogenous bases

Organic compounds containing nitrogen, components of nucleotides

Ribose

A five-carbon sugar found in RNA

Deoxyribose

A five-carbon sugar found in DNA

Steroids

Lipid molecules with a characteristic ring structure

Cholesterol

A steroid that is an important component of cell membranes

Triglycerides

Lipids composed of glycerol and three fatty acids

Unsaturated fats

Lipids with one or more double bonds in their fatty acid chains

Saturated fats

Lipids with no double bonds in their fatty acid chains

DNA

Deoxyribonucleic acid, the genetic material of organisms

RNA

Ribonucleic acid, involved in protein synthesis and other cellular functions

Double helix

The twisted ladder-like structure of DNA

Sugar-phosphate backbone

The structural framework of nucleic acids

Base pairs

Complementary nitrogenous bases that bond in DNA (A-T and G-C)

Purines

Nitrogenous bases with a double-ring structure (A and G)

Pyrimidines

Nitrogenous bases with a single-ring structure (C, T, and U)

Denaturation of protein

The loss of a protein's three-dimensional structure

Enzymes

Protein catalysts that speed up chemical reactions in organisms

Functional groups

Specific arrangements of atoms within molecules that give them characteristic properties

Activation energy

The minimum energy required for a chemical reaction to occur

Exergonic reactions

Chemical reactions that release energy

Endergonic reactions

Chemical reactions that require energy input

Substrate

The molecule(s) on which an enzyme acts

Active site

The region of an enzyme where the substrate binds

Products

The molecules resulting from an enzymatic reaction

Inhibitors

Substances that decrease or prevent enzyme activity

Coenzymes

Non-protein organic molecules that assist enzymes in catalyzing reactions

Cofactors

Inorganic ions or organic molecules required for enzyme function

Tour of the Cell Microscope

An instrument used to magnify small objects

Prokaryotic cells

Simple cells lacking a nucleus and membrane-bound organelles

Eukaryotic cells

Complex cells with a nucleus and membrane-bound organelles

Cell theory

The fundamental principles describing the nature of cells

Electron microscope

A microscope that uses electrons instead of light to produce images

SEM

Scanning Electron Microscope, used to study surface structures

TEM

Transmission Electron Microscope, used to study internal cellular structures

Light microscope

A microscope that uses visible light to magnify specimens

Field of view

The area visible through a microscope at a given magnification

Total magnification

The product of the eyepiece and objective lens magnifications

Nucleus

The control center of eukaryotic cells, containing genetic material

Nucleolus

A structure within the nucleus involved in ribosome production

Nuclear pore

Openings in the nuclear membrane that allow for transport

Nuclear membrane

The double membrane surrounding the nucleus

Cell membrane

The selectively permeable barrier surrounding cells

Cell wall

A rigid structure outside the cell membrane in plant cells

Cytoskeleton

A network of protein filaments that provides cellular structure

Cytoplasm

The contents of a cell between the nucleus and cell membrane

Cytosol

The liquid component of the cytoplasm

Endoplasmic reticulum

A network of membranes involved in protein and lipid synthesis

Golgi apparatus

An organelle involved in modifying, sorting, and packaging proteins

Ribosomes

Cellular structures where protein synthesis occurs

Lysosomes

Membrane-bound organelles containing digestive enzymes

Peroxisomes

Organelles involved in breaking down fatty acids and detoxifying chemicals

Vacuole

A membrane-bound sac used for storage in cells

Vesicle

A small, membrane-enclosed sac involved in transport within cells

Centrioles

Cylindrical structures involved in cell division in animal cells

Chloroplast

The site of photosynthesis in plant cells

Photosynthesis

The process by which plants convert light energy into chemical energy

Mitochondria

Organelles responsible for cellular respiration and energy production

Cellular respiration

The process of breaking down glucose to release energy

Cell Transport Cell membrane

The selectively permeable barrier surrounding cells

Phospholipid

A type of lipid molecule that forms the cell membrane

Cholesterol

A steroid that helps maintain membrane fluidity

Transmembrane protein

A protein that spans the entire cell membrane

Peripheral protein

A protein attached to the surface of the cell membrane

Integral protein

A protein embedded within the cell membrane

Glycoproteins

Proteins with attached carbohydrate chains on the cell surface

Glycolipids

Lipids with attached carbohydrate chains on the cell surface

Fluid mosaic model

The current model of cell membrane structure

Extracellular matrix

A network of proteins and carbohydrates outside animal cells

Transport proteins

Membrane proteins that facilitate the movement of substances across the membrane

Hydrophilic

Water-loving; describes molecules that interact with water

Hydrophobic

Water-fearing; describes molecules that do not interact with water

Amphipathic

Having both hydrophilic and hydrophobic regions

Passive transport

Movement of substances across a membrane without energy input

Active transport

Movement of substances across a membrane against a concentration gradient, requiring energy

ATP

Adenosine triphosphate, the energy currency of cells

Diffusion

The movement of molecules from areas of high to low concentration