Key Concepts in Cell Biology

A comprehensive collection of vocabulary flashcards based on key concepts in cell biology to aid in studying for an exam.

Cell

The smallest, basic unit of life responsible for all of life's processes.

Cell Theory

1. All organisms are made up of one or more cells.

2. The cell is the basic unit of all organisms.

3. All cells come from existing cells.

Prokaryote

A type of cell that is single-celled with no nucleus or membrane-bound organelles, DNA located in cytoplasm, ex. bacteria.

Eukaryote

A type of cell that can be single or multicellular and has membrane-bound organelles with DNA in the nucleus. There are two types of eukaryotic cells: plant cells and animal cells.

Unicellular

Organisms made up of one cell that carry out all functions of life.

Multicellular

Organisms made up of more than one cell that perform specialized functions.

DNA

Deoxyribonucleic Acid; the genetic material that contains the instructions for development, survival, and reproduction.

Atom

The basic building block of chemistry; the smallest unit of matter.

Smallest unit into which matter can be divided.

Molecule

A group of atoms joined together by chemical bonds.

Lipid

A hydrophobic (does not mix with water) fat molecule that stores energy in the body.

Protein

A molecule made up of smaller units called amino acids; essential for various body functions.

Amino Acid

The building blocks of proteins that combine to form different proteins.

Carbohydrates

Molecules that are the main source of energy for the body, including sugars, starches, and fiber

Nucleic Acid

Molecules that carry information in cells are made up of nucleotides. DNA is a type of nucleic acid that holds genetic material.

Phospholipid

A lipid that forms the cell membrane, consisting of a hydrophilic head and a hydrophobic tail.

Osmosis

The movement of water across a cell membrane.

Active Transport

Substances moving across the cell membrane with the use of energy (ATP).

Passive Transport

Substances moving across the cell membrane without using energy.

Diffusion

Molecules like to spread out from where there is more of them to where there is less.

Endocytosis

The process by which a cell takes in large molecules by engulfing them with its membrane.

Exocytosis

The process by which a cell releases substances to the outside by using the opposite process of endocytosis.

Mitosis

The process of cell replication where one cell divides to produce two identical cells.

Homeostasis

Constant maintenance of internal conditions in a cell or organism despite changes in the external environment.

Cell Membrane

A protective layer that covers a cell's surface and controls the movement of substances in and out of the cell. It is semi-permeable: only allows certain materials to cross in or out.

Cytoplasm

The fluid that fills the cell, containing water, salts, and various organic molecules.

Golgi Complex

Oganelle that prepares proteins and lipids for use inside and outside of the cell.

Mitochondria

Organelles known as the powerhouse of the cell, where cellular respiration occurs. Convert chemical energy from food into usable energy for the body.

Lysosome

An organelle that contains digestive enzymes for breaking down damaged organelles, waste materials, and foreign invaders in the cell.

Nucleus

The control center of the cell that stores DNA, DNA replication, and controls metabolism.

Rough ER

Ribosomes attached to its membrane (makes proteins)

Smooth ER

No ribosomes attached to its membrane, (make lipids)

Cell Wall (Plant Cells Only)

A rigid structure that provides support and protection to plant cells.

Vacuole

An organelle that stores water and other substances, particularly in plant cells.

Chloroplast

Organelles in plant cells that contain the green pigment called chlorophyll for photosynthesis.

Flagella

Hairlike structures that help PROKARYOTE move

Protein ENZYMES

Chemical aid in digesting food

Tissue

Groups of similar cells that work together to perform a specific function.

What are the 4 types of tissues.

1. Nervous

2. Epithelial

3. Connective

4. Muscle

Nervous Tissue

Made up of nerve cells and is used to carry messages throughout

the body

Epithelial

Protective tissue; provides a covering

Connective

Supports other tissues and binds them together

Muscle

Responsible for the movement of the body and organs through contraction.

Organ System

Group of organs that work together to perform specific body functions.

Photosynthesis

Plants use sunlight to change carbon dioxide and water into sugar and oxygen

Species

a group of organisms that are

very closely related.

Taxonomy

Science of describing, classifying and naming living things.

Domain

Domain represents the largest level of classification of organisms

Fungi

Yeasts, molds, and mushrooms.

Animalia

Birds, fish, reptiles, mammals.

Protista

Protists such as algae and slime molds

Autotroph

Make their own food

Heterotroph

Eat other organisms

Plantae

Plants and trees

Dichotomy Key

A tool that can be used to identify new organisms or objects in the natural world, such as plants, animals, or rocks.

Ribosomes

Makes protein by chains of amino acids (protein synthesis)