Chemistry is life Molecules make up components of cells Four major organic molecule types: 1.Carbohydrates (sugars, starches) 2.Lipids (fatty acids) 3.Proteins 4.Nucleic acids (DNA, RNA, ATP)

1. Carbohydrates Carbon + Hydrogen + Oxygen Ex. sugars/starches composed of single sugar units called monosaccharides, ex. glucose. can bond to form more complex compounds like table sugar, ex. sucrose (1 glucose + 1 fructose); 2 sugar units=disaccharide. CC C C C C glucose C C CC C

Carbohydrates Some important CHO’s are: – glycogen (how animals store food) – starch (how plants store food) – cellulose (plant cell wall compound)—most common CHO on planet – chitin (shells of bugs and some cells in fungi)

2. Lipids (Fats) Usually made of fatty acids and a molecule called glycerol fats are either saturated or unsaturated saturated fats, like lard, are the worst for humans unsaturated fats, like fish oils and plant oils, are better, and can be bonded together to make more complex fats called polyunsaturated fats.

Lipids/Fats (cont.) Lipids are extremely important: cell membranes lipids make other molecules like hormones (estrogen, testosterone) Ex.cholesterol is a lipid byproduct used to make hormones

The cell membrane is a fluid mosaic of phospholipids and proteins Figure 5.12 Fibers of the extracellular matrix Carbohydrate (of glycoprotein) Glycoprotein Microfilaments of cytoskeleton Phospholipid Cholesterol Proteins Plasma mem- brane Glycolipid Cytoplasm

3. Proteins Composed of units called amino acids only 22 amino acids exist, with 20 used for amino acids all share a similar structure amino acids form a peptide bond or sulfur bond with others as these chains of peptides form, they either form a spiral or a flattened sheet. Amino acid

3. Proteins protein spirals or sheets form complicated compounds Ex. hemoglobin in your red blood cells that carry oxygen: Hemoglobin

How proteins fold to become more complex proteins:

Modified proteins: enzymes Enzymes are amazing! Modified proteins Names end in –ase ex. Glucose is sugar, glucase is enzyme that breaks it down ex. Amylose is starch, amylase is enzyme Speed up chemical reactions Break compounds apart Put compounds together

Enzymes can break apart molecules OR put them together!

How enzymes work Two models: lock&key or induced fit Lock&key: exact fit of compounds to enzyme Induced fit: enzyme can “wrap” around compounds

4. Nucleotides 3 parts 1. phosphate molecules (phosphorus + oxygens) 2. a sugar 3. a base that contains nitrogen Sugar OH OPO OO CH 2 H O HH OH H H N N H N N H HH N Phosphate group Nitrogenous base (A)

Examples of Nucleotides: DNA (deoxyribonucleic acid)—holds genetic information RNA (ribonucleic acid)—takes information from DNA and makes proteins ATP (adenosine triphosphate) is important in transferring electrons; major energy carrier for cells

ATP uses Electrons to store/release energy – In living organisms, chemical energy is stored by using it to move electrons to more distant orbits.

– ATP powers nearly all forms of cellular work – The energy in an ATP molecule lies in the bonds between its phosphate groups Phosphate groups ATP Energy PPP P PP Hydrolysis Adenine Ribose H2OH2O Adenosine diphosphate Adenosine Triphosphate + + ADP Figure 5.4A

Structure of DNA Figure 2.21a Nucleotide = N-containing base, a pentose sugar, and a phosphate group Five nitrogen base types – adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U)

Molecules make Cells possible: Sugars for energy Proteins for building structures Lipids for cell membranes DNA/RNA for making more cells ATP for making energy possible

Molecules make Cells possible: Sugars for energy Proteins for building structures Lipids for cell membranes DNA/RNA for making more cells ATP for making energy possible

Prokaryotes vs. Eukaryotes DNA in single loop Very small No organelles Live in all environments DNA in chromosomes in nucleus Much larger Organelles handle complex cell tasks Live in restricted environments

Prokaryotic cells are structurally simpler than eukaryotic cells Prokaryotic cell Nucleoid region Nucleus Eukar yotic cell Organelles Colorized TEM 15,000  Figure 4.3A

Surface Area to Volume Ratio A small cell has a greater ratio of sur face area to volume than a large cell of the same shape 30  m 10  m 30  m 10  m Surface area of one large cube  5,400  m 2 Total surface area of 27 small cubes  16,200  m 2 Figure 4.2B

Eukaryotic cells—plants, fungi, animals, protists Nucleus present Membrane surrounds cell Cell wall may be present (plants, fungi, but NOT animals)

Plasma membrane Surrounds entire cell Made of two lipid layers Allows certain molecules in/out = “selectively permeable”

Nucleus—control center

Cytoskeleton—internal ‘skeleton’

Internal membrane system 3 important membranes : 1.Rough endoplasmic reticulum 2.Smooth endoplasmic reticulum 3.Golgi complex

Smooth endoplasmic reticulum has a variety of functions: 1.Synthesizes lipids 2.Processes toxins and drugs in liver cells 3.Stores and releases calcium ions in muscle cells

Rough endoplasmic reticulum makes membrane and proteins Ribosomes on the sur face of the rough ER produce proteins that are secreted, inserted into membranes, or transported in vesicles to other organelles

Lysosomes are sacs of enzymes that function in digestion within a cell Lysosomes in white blood cells destroy bacteria that have been ingested Lysosomes also recycle damaged organelles

The various organelles of the endomembrane system are interconnected structurally and functionally

Moving the cells around 3 ways: 1.Flagellum—cell extends cytoplasm into tail-like structure 2.Cilia—cell extends small hair-like structures 3.Pseudopodia—cell extends itself to move around

Human cells move too! 1.Lung cells & fallopian tube cells use cilia to move things around. 2.Male sperm cells use a flagellum to get to the egg. 3.White blood cells use pseudopodia to move between other cells and get to where they need to be.

Lecture Assignment 2 Pages in back of textbook Topic is cancer 1 page summary, handwritten, in your own words, due Thursday, April 17, at the beginning of class

Organelles Membrane surrounds them Important organelles: Nucleus Cell membrane Lysosomes/peroxisomes Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi apparatus Special organelles involved in energy: Mitochondrion—produces ATP (in all eukaryotes) In plants and some algae: Chloroplast—produces sugar from light energy

Mitochondria

Chloroplast

Can human diseases result from organelles? Yes! Lysosomes Mitochondria Peroxisomes (in plants) Even Cell Membranes! Aging? Chronic Fatigue Syndrome?

Quick Review! What are 5 organelles in the cell? In order, what organelles are responsible for moving the products of DNA to the Golgi Complex? What 3 things make up the cell membrane? What are the 4 foundational theories of biology? What are the 4 groups of biologically- important molecules?