Life is Cellular

Robert Hooke: 1st used the term cell Cell Theory All living things are made of cells Cells are the basic units of structure and function in living things of life New cells come from existing cells

Types of Cells Prokaryotes: no nucleus Eukaryotes: nucleus Nucleus: a large membrane enclosed structure that contains the cell’s genetic material in the form of DNA Prokaryotes: no nucleus Smaller and simpler Move by gliding or swimming bacteria Eukaryotes: nucleus Larger and complex Plants, animals, fungi, and protist

Eukaryotic Cell Structure Organelles: internal cell structures Cytoplasm: area outside the nucleus

Nucleus: contains the cell’s DNA Nuclear Envelope: nuclear membranes pores for movement Chromatin: DNA Chromosomes: compact chromatin Nucleolus: small dense region where ribosomes assembly

Other Organelles Rough ER: ribosomes on the surface Ribosomes: small particle of RNA for protein assembly Endoplasmic Reticulum: folded membrane Rough ER: ribosomes on the surface Synthesis of proteins Smooth ER: no ribosomes on the surface lipid synthesis & detoxification of drugs

More Organelles Golgi Apparatus: stack of membranes Modify, sort, & package proteins for storage Lysosomes: remove junk

Specialized Organelles Mitochondria: 2 membranes Inner membrane is folded up inside the organelle converts chemical energy from food to energy form cells can use

Specialized Organelles Plants Vacuoles: storage area Mainly plants Chloroplasts: capture sunlight energy and convert it into chemical energy through photosynthesis Plants only

Structure Cytoskeleton: network of protein filaments that helps maintain the cell’s shape Microtubules: hollow structures that maintain the cells shape Microfilaments: threadlike structures that make a flexible frame supporting the cell Movement Cilia: short hair-like projections Flagellum: whip-like projections

The Diversity of Cellular Life

Types of Organisms Unicellular Organisms - a single-celled organism grow, reproduce, respond to the environment, and transfer energy there are a greater number of single-celled organisms than multi-cellular organisms

Types of Organisms Multicellular Organisms - organism made of many cells organisms depend on the communication and cooperation among specialized cell to function Cell Specialization: cells throughout an organism develop in different ways for different tasks

Specialized Animal Cells Red Blood Cells - transport oxygen Pancreatic Cells - produce proteins have ribosomes and rough ER Muscle Cells - allow movement muscle cells generate force by using a dramatically overdeveloped cytoskeleton

Specialized Plant Cells Stomata: tiny opening on the underside of a leaf for the exchange of oxygen and carbon dioxide Guard Cells: regulate the exchange of the gases  

Levels of Organization Cell, Tissues, Organs, and Organ Systems Cells - first level of organization Tissues - a group of similar cells Muscle Epithelial (Skin) Nervous Connective Tissue

Levels of Organization Organs - groups of tissue Each muscle in your body is an individual organ Muscle Organs: muscle, nervous, and connective tissue

Organ Systems a group of organs work together to perform a function Nervous System Respiratory System Circulatory System Digestive System Immune System Skeleton System