Anatomy Exam 1

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What is Homeostasis? Why it is important for living systems

Homeostasis is the ability of an organism to maintain a consistent internal environment, or “ steady state”. It is important because it can normalize blood sugar regulation.

General steps of a negative feedback loop.

Mechanism that reverses deviation from the set point
Ex: Temperature regulation, Blood Sugar Regulation.

Positive feedback and when/where it occurs in the body

The stimulus is reinforced to continue in the same direction until a climactic event occurs
Ex: Childbirth contractions, Breast Feeding, Blood Clotting.

Atom and the roles of Protons, Neutrons, and Electrons.

Atoms is the smallest quantity of an element
Protons is positive charge
Neutrons is no charge
Electrons is negative charge

Atomic number, Mass number, and Charge State from Subatomic particles

Atomic number, Protons, and Electrons are bottom left number of Element.
Mass number is top left number of Element
Neutrons if top left minus bottom left.

Atoms, Ions, Isotopes, Molecules, and Compounds

Atoms is smallest quantity of an element. It composed of Protons, Neutrons, and Electrons.
Ions is an atom with an electric charge Positive and Negative. Cation when ion with positive. Anion is ion with negative charge

Isotopes is same element but different mass number. (the bottom left number)
Molecules is 2 or more atoms bonded together (same element)
Compounds is composed of two or more different elements joined by Chemical Bonds

Ionic Bonds

The ongoing close association between ions of opposite charge (give electron away)

Covalent Bonds

Share electrons in a mutually stabilizing relationship
Stronger than ionic bonds (strongest attach)

Hydrogen Bonds

Weak Negative (-) oxygen attach to weak Positive (+) of hydrogen fro covalent bonds

Carbohydrates

Molecule composed of Carbon (C), Hydrogen (H), and Oxygen (O)
Generic formula: CH2O

Also called Sugars or Saccharides

All body cells can use glucose to create energy

Carbohydrates: Monosaccharides

A Carbohydrate monomer
Hexose sugars (Top rows)
Pentose Sugars (Bottom row)

Carbohydrates: Disaccharides

A Carbohydrate Dimer
Sucrose = table sugar
Lactose = milk sugar

Maltose = Malt sugar
Body breaks them down into components and then uses them individually

Carbohydrates: Polysaccharides

Can be thounsands of monosaccharides

Starches - Glucose polymers, found in plants, easy to digest

Glycogen - Glucose polymers, found in animals, how we store glucose in our bodies

Cellulose- glucose polymer, found in plants, not digestable

Lipids

Made of mostly hydrocarbons, few oxygen atoms
Non polar; hydrophobic

Lipids: Triglycerides

Glycerol + 3 fatty acid chains
Major source of fuel for body

Saturated and Unsaturated Fats

Saturated: no double bonds maximum number of hydrogen atoms ( pack together tightly)

Unsaturated: one double bond , forms a kink (cannot pack together tightly)

Lipids: Phospolipids

Phosphate group + Glycerol + 2 fatty acid chains
The phosphorous head is polar, the fatty acid chains are non-polar

• Amphipathic

Lipids: Steroids

4 Hydrocarbon rings bonded to a variety of other atoms and molecules

Protein

Monomer: Amino acids
Polymer: Polypeptide or protein
Peptide Bond

Found in all tissues and organs

N-Terminus and C-terminus

Protein: Structure of an Amino Acid

Central carbon atom

• called alpha carbon

An Amino group

Carboxyl group

Hydrogen

Variable group

Proteins: The Formation of Peptide Bonds

Proteins: Form= Function

Primary

Secondary

Tertiary

Quaternary

Factors that affect protein folding: (Denature)

• Temperature

• pH

• Salt

• ETC

Nucleic Acids

Monomer: Nucleotide

Polymer: Nucleic Acid

DNA and RNA

5’ and 3’ Ends

3’- CGGGTCACGTAC- 5’

RNA: 5’ GCCCAGUGUATG 3’

DNA: 5’ GCCCAGTGCATG 3’

Pentose Sugars

The Nucleus

Stores DNA

• Regulates gene expression

Nucleolus creates Ribosomes

Nuclear envelope with pores

Chromatin versus Chromosome

Rough ER

Covered in Ribosomes giving it a rough/bumpy appearance

Synthesis of membrane proteins or secreted proteins

Smooth ER

Lipid synthesis

Steroid Hormone Synthesis

Stores Ca2+

Golgi Apparatus

Stack of Flattened discs

• Look like stack of pancakes

Sorts, Modifies, and ships proteins made in Rough ER

Cis-Face ————> Trans-Face

Vesicles

Membrane-Bound transport vehicles

Transport materials between the above organelles and the plasma membrance

Lysosomes

A Specialized vesicle

Contains enzymes that break down and digest unneeded cellular components

In some immune cells they breakdown foreign materials like bacteria

Peroxisomes

Membrance-bound organelle that contains mostly enzymes

Lipid metabolism

Chemical Detoxification through Peroxide

• Complicated chemistry

The Plasma Organelles

Cholesterol

• Scattered throughout hydrophobic regions

• Strengthens Membrance

• Stabilize Membrane at extreme temperatures

• Lipid and protein components

Factor Affecting Membrane Fluidity

Saturated (more solid; less fluid)

Unsaturated (more fluid; distribution of unsaturated tails matters too)

Length of tails

Cholesterol

The Plasma Membrane (Protein Components)

Integral Proteins

• Embedded in the plasma membrane

Peripheral Proteins

• Closely associated to the plasma membrane

Plasma membrane (Funtion)

Physical Barrier: establishes flexible boundary, protects cellular contents, and supports cell structure. Phospholipid bilayer separates substances inside and outside the cell

Selectively Permeable Boundary: Regulates entry and exit of ions, nutrients, and waste molecules through the plasma membrane

Electrochemical Gradients: Establishes and maintains an electrical charge difference across the plasma membrance

Communications: Contains receptor that recognize and respon to molecular signal

The cell Cycle

Interphase- cell is not dividing

• G1

• S

• G2

Mitosis