Chapter 7.1 & 7.2: Cells
What are cells? Basic part of all living organisms Make up tissues
Why are they called cells? Robert Hooke 1st person to view “cells” Compared what he saw to a monk’s room
Cell Theory Smallest unit of living things that can carry out activities necessary for life Composed of parts called organelles
What we know about cells (cont.) 3. Cells can only arise from other cells
Studying Cells Scanning Electron Microscope (SEM) Transmission Electron Microscope (TEM)
What we know about cells (cont.) 3. Cells can only arise from other cells
Types of Cells: 1. Eukaryotic Cells Contains membrane bound organelles Have a nucleus Ex. Our cells
2 Types of Cells (cont.) 2. Prokaryotic Cells No membrane bound organelles or nucleus Unicellular Ex. Bacteria
Comparing: Prokaryotic & Eukaryotic Cells Cell membrane Cytoplasm DNA
Why do the similarities matter? Scientists believe eukaryotic cells evolved from prokaryotic cells
What are Organelles?
What are Organelles?
What are Organelles? Structures in a cell Have specific functions
Nucleus Controls cell activities Contains genetic information (DNA in form of Chromosomes) Surrounded by nuclear membrane (envelope)
Nucleolus Located in nucleus Produces ribosomes
Ribosome Helps manufacture proteins Float free and attach to endoplasmic reticulum
Endoplasmic Reticulum Rough and smooth types Proteins and lipids assembled here
Golgi Apparatus Modifies and packages proteins and other materials to ship out of cell
Chloroplast Only in plants Traps light & converts it to energy (glucose) Process: Photosynthesis Contain pigment called chlorophyll
Mitochondria Energy generator AKA Powerhouse of cell Breaks down glucose
Vacuole Stores food, water and enzymes
Centrioles Used in cell division Only in animal cells
Cell Wall Only in plant cells Stiff & rigid, outside of cell membrane Supports and protects cell
Cilia & Flagella Hair-like structures on cell surface Assist in movement Flagella: few & long Cilia: many & short
Lysosomes Use enzymes to digest worn out organelles, viruses & bacteria
Cytoskeleton Microtubules & Microfilaments Provides framework and support Thin protein fibers
Cytoplasm Clear, jelly-like material Provides support to cell Site of many chemical reactions
Plasma (Cell) Membrane Lipid bilayer Selectively permeable Regulates what enters & leaves cell Assists in homeostasis