Cell Structure and Function
What is a cell? Smallest particle or building block of life Made up of four elements – (CHON) Majority of structure is protein Vary in size (2 micrometers to over a meter) Shape controls function Example: white blood cells destroy bacteria
What is Cytology? The study of the structure and the function of cells.
What is the main structure of a cell? Nucleus - contains DNA Plasma membrane - lipid bilayer barrier that separates the inside with outside environment of the cell Cytoplasm – cellular material outside the nucleus and inside the plasma membrane
What are organelles? Found in the cytoplasm Metabolic machinery Different Types Endoplasmic reticulum – fluid-filled tubules that twist in cytoplasm (smooth ER vs. rough ER) Golgi apparatus – flat membranous sac that packages proteins Mitochondria – sausage-shaped that help make ATP for energy
What are the organelles? Ribosomes – tiny, round proteins that allow protein synthesis Lysosomes – membrane bags that have digestive enzymes to get rid of foreign substances Peroxisomes – membranous sacs that use oxygen to get rid of harmful substances Cytoskeleton – network of protein structures that gives internal framework Centrioles – rod-shaped bodies that form the mitotic spindle during cell division
Cell Structure Drawing
Cell Structure Drawing
Cell Structure Drawing
What are the main functions of the cell? Metabolize Digest foods Get rid of wastes Reproduce Grow Move Respond to a stimulus (irritability)
What are two types of membrane transport? Passive transport – no energy is needed to transport substances through cell membrane diffusion – particles that are in random motion and move to an area where there is less particles filtration – water and solutes are forced through a membrane by fluid or hydrostatic pressure
What are two types of membrane transport? Active transport – the use of ATP (energy) to move substances across the membrane solute pumping – the use of protein solute pumps to get substances across membrane (sodium-potassium pump) bulk transport – endocytosis (phagocytosis) vs. exocytosis
What are the types of diffusion? Simple diffusion – no assistance is needed to get particles or solutes across the plasma membrane Osmosis – the movement of water across the plasma membrane Facilitated diffusion – proteins in the plasma membrane are needed to get certain substances (glucose) across
Diffusion Drawings
Active Transport Drawing
Sodium-Potassium Pump Drawings
Bulk Transport Drawing
What is cell division? Interphase – cell growth & metabolic activity Cell division (2 parts) Mitosis – 4 phases (prophase, metaphase, anaphase, telophase) Cytokinesis – division of the cytoplasm to make two daughter cells
Mitosis Diagram
What is protein synthesis? Need DNA (genes) Need RNA mRNA tRNA rRNA Two Steps (2 T’s) transcription – DNA is copied into mRNA translation – mRNA is decoded to make proteins
Protein Synthesis Diagram