CELLS

The Cell The basic unit of life Self-replicating Bound by a membrane Contains biomolecules like DNA, proteins and sugars Can exist as: Single-celled organisms (e.g. bacteria, yeast) Sub-unit in a multi-cellular organism (e.g. plants, animals) Cells are specialized in their structure and function (e.g. brain cells, blood cells, etc)

Single-celled Organisms Bacteria Yeast (a type of fungus)

Specialized Animal Cells Red Blood Cells Cheek Cells Sperm and Egg Cells

Cell Theory Cheek Cells All living things are made up of one or more cells and the products of those cells. Cells are the functional units of life. All cells come from pre-existing ones. Sperm and Egg Cells

Types of Cells Prokaryotic Cells Eukaryotic Cells Cheek Cells Simple Cells No nucleus No organelles More complex cells Nucleus Membrane-bound organelles e.g. plant cells, animal cells, protists and fungi e.g. bacteria

Organelles Little “organs” of cells Membrane-bound Allow for cellular functions like: DNA replication cell division excretion of wastes Cheek Cells

ANIMAL CELL Cheek Cells

PLANT CELL Cheek Cells

CELL WALL protects the cell gives shape is made of cellulose Cheek Cells protects the cell gives shape is made of cellulose A cell wall is found in plants, algae, fungi, & most bacteria.

CELL MEMBRANE Outer covering, protective layer around ALL cells For cells with cell walls,the cell membrane is inside the cell wall Allows food, oxygen, & water into the cell & waste products out of the cell. Cheek Cells

CYTOPLASM gelatin-like inside cell membrane constantly flows Cheek Cells gelatin-like inside cell membrane constantly flows aka protoplasm

CYTOSKELETON scaffolding-like structure in cytoplasm Cheek Cells scaffolding-like structure in cytoplasm helps the cell maintain or change its shape made of protein

NUCLEUS Directs all cell activities Cheek Cells Directs all cell activities Contains instructions for everything the cell does These instructions are found on a hereditary material called DNA Usually the largest organelle

NUCLEOLUS Cheek Cells Aka “little nucleus” Found in the nucleus

ENDOPLASMIC RETICULUM Cheek Cells Network of tubes or membranes Carries materials through cell Can be Smooth (no granules on the surface – the granules are ribosomes) Rough (granules on the surface)

RIBOSOME Small bodies free or attached to E.R. Cheek Cells Small bodies free or attached to E.R. Their function is to produce proteins

MITOCHONDRION Bean-shaped with inner membranes Cheek Cells Bean-shaped with inner membranes Place where sugar molecules are broken down into energy Cellular respiration

GOLGI BODIES Compartment in which proteins are sorted and modified Cheek Cells Compartment in which proteins are sorted and modified Stack of membrane-bound vesicles which package substances to be transported around the cell

VACUOLES Fluid-filled sacs found in both plants and animals Plants usually have few larger vacuoles Animals usually have smaller vacuoles Store food, water, waste Plants need to store large amounts of food Cheek Cells

LYSOSOMES Small, round structures with a membrane Break down larger food molecules into smaller molecules Digestion Attack “foreign bodies” Protection Digest old cell parts Not too common in plants Cheek Cells

CHLOROPLASTS Green, oval structures found in plant cells Cheek Cells Green, oval structures found in plant cells Contain the green pigment chlorophyll Place where energy from sun is utilized to make food for the plant Photosynthesis