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38 terms

Molecules: Cell structure and functions1.1

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Cell
The basic unit of life.
Plant Cell
A type of cell characterized by a rigid cell wall and the presence of many chloroplasts, a cell containing endoplasmic reticulum, a nucleus, Golgi body, a vacuole, a cell wall, a cell membrane, chloroplasts, cytoplasm, mitochondria, ribosomes
Eukaryote cell
Has nucleus, many organelles. examples are: animals and plants; larger than Prokaryote cells
Prokaryote cell
lacking a membrane-bounded nucleus and organelles; the cell type also known as bacteria; smaller than Eukaryote cell
Cell Wall
Inflexible (rigid) barrier found only in plants. Helps provide shape and structure. Also acts as a pressure vessel, preventing over-expansion when water enters the cell. Found in plant, bacteria, and fungi; not found in animals and protozoa.
Cell Membrane
Flexible barrier between the cell and the environment. Is selectively permeable, which means that it allows only certain substances to pass through it.
phospholipid bilayer
plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside. heads-face the watery substance on both sides
Cytoplasm
The "living" part of the cell, extending from the nucleus to the cell wall.
All of the cell organelles and organic materials in the cell excluding the nucleus.
Organelle
The name for a membrane-bound structure with a specific cell function.
Nucleus
Organelle that acts as the control center for the cell and houses genetic information (DNA).
Chromosome
a structure in the nucleus that contains hereditary material
Nucleolus or Nucleoli
Structure(s) found inside the nucleus that produce ribosomes.
Chloroplast
a structure of plant cells that captures energy from sunlight and uses it to produce food; site of photosynthesis
Endoplasmic Reticulum
Organelle composed of a series of folded membranes. Acts as a transportation network for proteins and enzymes.
May be "rough" (#3) or "smooth" (#4).
Endoplasmic reticulum
a cell structure that transports proteins and other materials from one part of the cell to another.
Smooth ER
The site of lipid synthesis and responsible for breaking down toxic substances. (no ribosomes)
Rough ER
A network of interconnected membranous sacs covered with ribosomes that make membrane proteins and secrete proteins.
Golgi body
receives proteins; sorts, modifies, packages, and distributes them to other parts of the cell or exit the cell.
Vacuole
an organelle that stores food, water, and other materials needed by the cell; plant- large; animal- many small;
Pili
short projections that help attach prokaryotes to surfaces for reproduction
Flagella
long, whiplike structures that aid in locomotion and feeding and are less numerous than cilia; present in both prokaryotes and eukaryotes
Cilia
short, hair-like structures that enable movement of cells or aid in the movement of other materials; present in both prokaryotes and eukaryotes
Prokaryote
An organism that possesses prokaryotic cells; cells that lack a nucleus and other membrane-bound structures. The only prokaryotes are bacteria.
Eukaryote
An organism that possesses eukaryotic cells; cells that possess a nucleus and other membrane-bound structures. Eukaryotes include all organisms (animals, plants, fungi, and protists) but bacteria.
Three components of the "cell theory":
1. All living things are composed of cells.
2. Cells are the basic unit of organization (structure and function) in living things.
3. All cells come from preexisting cells.
Ribosomes
Organelles that serve as the site for protein synthesis (where proteins are assembled).
Cytosol
Liquid part of the cell that surrounds and suspends the cells.
Golgi Body (Apparatus)
Packages, modifies, and distributes newly synthesized substances. Activates enzymes.
The "Post Office" of the cell...
(Shown as the pink, folded structure in the diagram)
Vacuole
Fluid-filled storage sac (large in plants, small in animals).
Peroxisomes
Organelle in liver cells; contain enzymes (such as catalase) that help detoxify harmful substances such as alcohol and hydrogen peroxide.
Mitochondria
Bean shaped organelle where glucose is broken down to release energy by cellular respiration. Potential energy is stored in the form of ATP, a chemical that acts as the cell's "currency".
The "powerhouse" of the cell.
Chloroplasts
Organelle capable of photosynthesis; using light energy, this organelle combines carbon dioxide and water to form glucose (sugar).
Chlorophyll
A green pigment found in chloroplasts that absorbs light energy.
Microtubules or Cytoskeleton
The "scaffolding" of the cell; provides structure and support.
Cilia and Flagella
Structures that help cells move.
Cilia
Hair-like structures that help paramecium move around.
These structures are also found lining your respiratory tract to move mucus across its surface.
These structures are also found lining the oviduct and help move eggs through the female reproductive tract.
Flagella
This whip-like structure helps move single-celled organisms (such as Euglena).
This structure also moves sperm cells.
Lysosome
This organelle contains digestive enzymes used to "split" substances apart.
This organelle also helps to breakdown decaying and worn-out cell parts.