The Cell
#1 Mitochondria
Mitochondria Nickname: Batteries Structure: bean shaped Function: provides energy for the cell (powerhouse of the cell)
Mitochondria
#2 Nucleus
Nucleus Nickname: Structure: Function: Brain -central, large sphere -surrounded by a nuclear membrane -contains the chromosomes (DNA) -controls all cell activity
Nucleus Chromatin Mitochondria Endoplasmic Reticulum
#3 Endoplasmic Reticulum
Endoplasmic Reticulum Nickname: Subway System Structure: -tubes that connect the nucleus to the cytoplasm -Rough ER has ribosomes -Smooth ER has NO ribosomes Function: -transports materials
Rough Endoplasmic Reticulum Has ribosomes
#4 Cell Membrane
Cell Membrane Nickname: skin Structure: -has 2 layers -it is the outer boundary Function: 1) Holds the cell together 2) Controls what goes in and out of the cell
#5 Golgi Bodies
Golgi Bodies Nickname: Packaging Factory Structure: -folds of membrane Function: -packages materials for transport
#6 Lysosome
Lysosome Nickname: Stomach Structure: -small sphere -contains digestive juices Function: -digests molecules
Lysosomes
#7 Vacuole
Vacuole Nickname: Suitcase Structure: -large bubble like container Function: -stores food or waste
Vacuoles
#8 Cytoplasm
Cytoplasm Nickname:? Structure: -jelly like fluid that fills the cell Function: 1) gives the cell shape 2) contains nutrients/food for the cell
#9 Leave it blank for now
#10 Nucleolus
Nucleolus Nickname: brain in a brain Structure: -small sphere inside nucleus Function: -control center for nucleus
Nucleus Nucleolus
Movie: Parts of an Animal Cell
Plant Cells vs. Animal Cells Similarities & Differences
Plant Cells vs. Animal Cells Similarities Similarities & Differences -nucleus -cell membrane -cytoplasm These are the most important organelles b/c they all cells have them.
Plant Cells vs. Animal Cells Differences Similarities & Differences Animal Cell Round shape Lysosomes No cell wall No chloroplasts Plant Cell Square shape No lysosomes Cell wall Chloroplasts
Cell Specialization Cells vary in: -shape -size -internal structure Why is this important? -different cells perform different functions
Nerve Cells
Nerve Cells Characteristics: -very long allows messages to go from brain to hand -branching messages sent to coordinate many activities all at the same time
Skeletal Muscle Cell
Skeletal Muscle Cell Characteristics: -very long -many nuclei lots of nuclei to control the whole length of muscle -many mitochondria muscle requires a lot of energy
Red Blood Cells
Red Blood Cells Characteristics -concave shape -very small allows cell to bend in order to fit through tiny blood vessels
Movie: Types of Human Cells
How do things get in and out of the cell?
The cell membrane controls what goes in and out of the cell a.k.a. Selective Permeability Selective: choosy Permeable: porous or has holes Ex: rain coat is not permeable Sweater is permeable
The cell membrane must be permeable (have holes in it) because: 1. Nutrients, water and oxygen must enter 2. Waste must exit (a build-up up is toxic!) The cell membrane is selective because: 1. Not everything can enter or exit (ex: viruses)
Molecules that must be able to get in and out of the cell Nutrients Oxygen Water Waste Virus
Entering & Exiting There are 3 ways to enter and exit the cell: 1. Diffusion 2. Osmosis 3. Endocytosis a. Phagocytosis b. Pinocytosis Passively (no effort from the cell) Actively (cell makes it happen)
1. Diffusion The movement of molecules from an area of high concentration to an area of low concentration
2. Osmosis The movement of water from an area of high concentration to an area of low concentration
3. Endocytosis/Exocytosis Sometimes, molecules are too large to pass through the cell membrane. Endocytosis is used for large molecules to enter a cell. a) Phagocytosis cell eating b) Pinocytosis cell drinking Exocytosis is used for large molecules to exit a cell.
Endocytosis
Endocytosis The cell membrane invaginates (forms a pocket) which engulfs the large molecules and brings them into the cell.
Movie: Endocytosis & Exocytosis
Movie: The Double Helix
DNA DeoxyriboNucleic Acid DNA is genetic information. The blueprint for the development & appearance of every living thing. Shape: Double helix
Chromosomes are made up of DNA They are found in the nucleus
Chromosomes Humans have exactly 46 chromosomes.
2 Categories of Cells Somatic Cells (body cells) Ex: skin cells bone cells These cells are diploid 46 chromosomes Divide by Mitosis
But what happens when a baby is made? A baby is created from a sperm & an egg Does that mean the baby has 46 + 46 chromosomes (total: 92)? What has to happen for a baby to get only 46 chromosomes?
2 Categories of cells Somatic Cells (body cells) Gametes (reproductive cells) Ex: skin cells bone cells Ex: sperm cells ovum (egg cells) These cells are diploid 46 chromosomes Divide by Mitosis These cells are haploid 23 chromosomes Divide by Meiosis
But what happens when a baby is made? Since the sperm and egg have only half of the necessary chromosomes (23 each) together they will create a baby with exactly 46 chromosomes.
In order to produce more cells, cells divide 2 types of Cell Division: -Mitosis -Meiosis
Do Somatic Cells Need to Reproduce?
Do Somatic Cells Need to Reproduce? Yes! To replace old cells To replace damaged cells For growth
Mitosis (somatic cells) 1. Everything inside the cell is duplicated (copied). 2. The cell then divides into two identical cells. These cells are identical in every way. They are clones. They are diploid.
Mitosis Chromosomes are duplicated Cell Division occurs (Mitosis)
Meiosis (reproductive cells) 1. Everything inside the cell is duplicated (copied). 2. The cell then divides TWICE to form 4 cells with half the number of chromosomes These are the gametes (egg and sperm cells) They are haploid
Meiosis Chromosomes are duplicated 1 st Cell Division 2 nd Cell Division
Movie: Mitosis
Phase 1: Interphase 1. Each chromosome makes a copy of itself 2. Chromosomes still appear as Chromatin
Phase 2: Prophase 1. Chromosomes now visible 2. Spindle fibers stretch across the cell 3. Nuclear membrane disappears
Phase 3: Metaphase 1. Chromosomes line up at center of cell 2. Spindle fibers attach to chromosomes
Phase 4: Anaphase 1. Spindle fibers pull chromosome pairs apart towards opposite sides of cell
Phase 5: Telophase 1. Nuclear membrane reappears 2. Cell pinches apart to form 2 new cells
Movie: Meiosis