Cells

Metric Review Starts with the base units, then can get larger or smaller

Metric Review Centimeter = cm Millimeter = mm Prefix Symbol Exponent Multiplier centi- c 10-2 1/100 (one hundredth) milli - m 10-3 1/1000 (one thousandth) micro - µ 10-6 1/1,000,000 (one millionth) nano- n 10-9 1/1,000,000,000 (one billionth) Centimeter = cm Millimeter = mm Micrometer = µm Nanometer = nm

Metric Review

Metric Review 10-2 m = 0.01 m = 1 cm 10-3 m = 0.001 m = 1 mm (1000 µm) 10-6 m = 0.000001 m = 1 µm (1000 nm) 10-9 m = 0.000000001 = 1 nm

Converting inches and cm 1 in = 2.54 cm Converting inches and cm How many cm in… 1 inch? 2 inches? 5 inches? 12.5 inches? How many inches in… 5 cm 32 cm

How large is _____________ in… Take a ruler and measure your object in: Inches Centimeters: Meters: Millimeters: Micrometers: Nanometers: 1 in = 2.54 cm

What are cells? Recall:

Cells Life’s fundamental unit of structure

Organelles A functioning group of biomolecules

Molecule A chemical structure containing two or more atoms

Atom The basic unit of matter

Cells – what’s the big deal? Cells are the ‘simplest’ or lowest level of organization that have all the characteristics of life (made of cells, use energy, respond to stimuli, reproduce, growth, adapt to environment, DNA/RNA) But pretty complex with organelles, all made up of biomolecules, which are made of atoms

How did we learn this? Microscopes! Started with simple glass – similar to ‘magnifying glass’ – 100AD 6x magnifying power

How do we know this? Robert Hooke – 1665 – first discovered cells – looked at cork 50x magnifying power Antony Van Leeuwenhoek – 1670’s ‘perfected’ the lens 270x magnification power

Modern Microscopes Light microscope – common in schools today Light passes through specimen and then through glass lenses to enlarge image Up to 1000x

Modern Microscopes Electron Microscopes – Focuses beams of electrons through a specimen or onto its surface Up to 10,000,000 x

Modern Microscopes Scanning electron microscope (SEM) Used to see the detailed architecture of cell surfaces

Modern Microscopes Transmission Electron Microscope Used to study the internal cell structure

Modern Microscopes We can add ‘fluorescence’ to help see and highlight specific parts of a cell

Cells

Cell Theory In the 1800s, studies with the light microscope led to cell theory, which states that all living things are composed of cells and all cells come from other cells.

Cell Size be large enough to contain structures needed to survive and reproduce remain small enough to allow for a proper surface area-to-volume ratio

Proper Surface Area-Volume Materials (O2, sugars, CO2, wastes) need to move in and out of cell Moves across the plasma membrane

Proper Surface Area-Volume The greater the surface area-volume ratio, the more exchange of materials can happen. Total volume 3 1 2 6 Total surface area Surface-to- volume ratio 27 units3 54 units2 162 units2

Surface-to- volume ratio 27 units3 Figure 4.2a Total volume 3 1 2 6 Total surface area Surface-to- volume ratio 27 units3 54 units2 162 units2 Figure 4.2a Effect of cell size on surface area

Hydrogen peroxide how stuff works

Which will produce more bubbles? Potatoes have an enzyme that breaks down hydrogen peroxide causing it to bubble. The more surface area, the more enzyme that can interact, the more bubbles

Which will produce more bubbles? 3x3 cm potato or 3x3 cm potato diced up?

Potato Video

Post potato video Why did the diced potato create more bubbles? There were more pieces of small sized potato What does that mean? More of the enzyme can react with the hydrogen peroxide

Proper Surface Area-Volume The greater the surface area-volume ratio, the more exchange of materials can happen. Total volume 3 1 2 6 Total surface area Surface-to- volume ratio 27 units3 54 units2 162 units2

Prokaryote Cells Vs. Eukaryote Cells All are single celled organisms found in Domains Archaea and Bacteria

More than Domains and Kingdoms Mnemonic: Did King Phillip Cry Out “For Goodness Sakes!”?

Prokaryote Cells Vs. Eukaryote Cells All are single celled organisms found in Domains Archaea and Bacteria Prokaryotic cells are smaller and simpler in structure

Prokaryote Cells Vs. Eukaryote Cells In a prokaryotic cell, the DNA is coiled into a region called the nucleoid (nucleus-like) and no membrane surrounds the DNA.

Prokaryote Cells Vs. Eukaryote Cells Eukaryotic Cells More complex Contains a membrane-enclosed nucleus many membrane-enclosed organelles that perform specific functions.

How did complex life form?

Inside-Out Theory

What’s inside the cell?

Rough endoplasmic reticulum Chromatin CYTOSKELETON Microtubule Figure 4.4a NUCLEUS Nuclear envelope Nucleolus Rough endoplasmic reticulum Chromatin CYTOSKELETON Microtubule Microfilament Intermediate filament Ribosomes Peroxisome Smooth endoplasmic reticulum Plasma membrane Figure 4.4a An animal cell Golgi apparatus Centrosome with pair of centrioles Lysosome Mitochondrion

Rough endoplasmic reticulum Nuclear envelope Figure 4.4b NUCLEUS Rough endoplasmic reticulum Nuclear envelope Smooth endoplasmic reticulum Nucleolus Chromatin Mitochondrion CYTOSKELETON Microfilament Microtubule Central vacuole Ribosomes Chloroplast Cell wall Plasmodesma Figure 4.4b A plant cell Cell wall of adjacent cell Golgi apparatus Peroxisome Plasma membrane