The Cell: Plants and Animals

Levels of Organization Organisms ↓ Organ System (group of organs working together) Organ (tissues working together) Tissues (group of cells working together) Cell (basic unit of life) Organelles (components of cell that have special functions to carry out life processes such as movement, growth, waste removal, reproduction, etc)

Cell Theory Cell Theory All living things are made up of 1 or more cells Cells are the basic unit of life All cells come from the division of other cells

The Animal Cell

The Plant Cell

Cell Membrane Roles: Protective barrier Controls what goes in/out (eg. nutrients, waste) Structure: 2 layers of lipids (fat molecules with phosphate groups) = phospholipid bilayer

Cell Wall Roles: Protection Gives plant support & rigidity Structure: Outermost wall in plant cells, bacteria, fungi and some algae Surrounds cell membrane Porous

Cytoplasm Roles: Fluidity allows for movement of nutrients and organelles around the cell Structure: Made up of cytosol (fluid gel substance) and organelles

Cytoskeleton Roles: Helps maintain the cell’s shape Structure: Internal network of fibres made up of protein filaments

Nucleus Roles: Control center of the cell that directs all of the cell’s activities. Contains our genetic info, DNA, which is combined with proteins to make chromatin During cell division, chromatin condenses into chromosomes

Nucleus Structure: Nuclear envelope that surrounds nucleus with nuclear pores Pores allow movement of materials in/out Nucleolus is dense area where components of the ribosomes are made

Ribosomes Roles: Where proteins for cell are made Structure: Small dense organelles free-floating in cytoplasm or attached to rough endoplasmic reticulum

Rough Endoplasmic Reticulum Roles: Where proteins are made Structure: Series of small tubes or folds Ribosomes are attached (hence “rough” part of name)

Smooth Endoplasmic Reticulum Roles: Makes fat molecules Structure: Series of small tubes or folds No ribosomes are attached (hence “smooth” part of name)

Golgi Apparatus Roles: Receives a fat or protein from ER and “prepares” it for delivery (using a vesicle) within the cell or outside of the cell Structure: Stack of flattened membranes

Vesicles Roles: Store & transport nutrients, waste and other materials. Structure: Membrane-bound sac

Vacuoles Roles: Store nutrients, waste and other materials Central vacuole in plant stores water to maintain rigidity of plant Structure: Membrane bound sac

Lysosomes Roles: Contain special proteins called enzymes that breaks down food, dying/damaged cells as well as foreign bacteria Structure: Membrane-bound vesicle with enzymes in it Released from Golgi Apparatus

Mitochondria Roles: Singular: “mitochondrion” Powerhouse of the cell = provides energy Uses chemical energy stored in food and converts it into an useful form for cell Structure: 2 membranes – inner & outer Numerous folds within: cristae

Chloroplasts Roles: Responsible for plant cellular respiration (photosynthesis) Structure: 2 membranes Inside, discs called thylakoids stacked together form a column called granum Thylakoids contain green pigment called chlorophyll which kick-starts photosynthesis

Centrioles Roles: Paired structures that are involved in cell division (mitosis) Structure: Made up of protein filaments