APK2105C exam 1

Anatomy

Study of body structures

Physiology

Study of body functions

Applied Physiology

How structure and function are related

Hierarchy of Structural Organization

Atoms - Molecule - Organelle - Tissue - Organ - Organ system - Organism

Cells

the basic living building blocks of the body; smallest libing units of the body

Tissue

groups of similar cells working together to perform a function

Tissue Types

Nervous, Muscle, Epithelium, Connective

Nervous Tissue made of…

neurons and neuroglia; neurons- send electrical signals through the body; neuroglia- support and protect nerve cells

How it works:

• branches send and receive signals

• helps with sensation, communication, and movement control

Muscle tissue main function is…

movement

Also helps with (secondary function):

• body temperature regulation

• stretching (extensibility)

• elasticity

• contracting

• responding to stimuli (excitability)

Epithelial tissue

Layers of tightly packed cells, in a sheet-like arrangement

• attached to a basement membrane and connective tissue

Epithelial tissue can be:

• simple (one layer)

• stratified (multiple layers)

Form glands

• exocrine glands

• endocrine glands

Connective tissue main function:

Support

• most abundant and diverse tissue type

• contains fewer cells and more extracellular material

• includes bone and blood

Do organ systems overlap?

Yes

Skeletal system

• bones

• cartilage ligaments

• bone marrow

Provides Support!

Muscular System

• skeletal muscles and associated tendons

Provides movement and protection/support for other tissues

Nervous System

• brain

• spinal cord

• peripheral nerves

• sense organs

response to stimuli and movements

Endocrine System

• pituitary gland

• thyroid glan

• pancreas

• adrenal glands

• gonads

• endocrine tissue in other systems

metabolic activity and energy use

Cardiovascular System

• heart

• blood

• blood vessels

Distribution

Epithelial tissue

one layer that separates the inside of the body from the outside environment

Semipermeable membranes

help separate fluid compartments in the body, helps with protection and selective movement of substance

Homeostasis

Maintenance of stable internal conditions in the body

How does homeostasis help to regulate the extracellular fluid (ECF)

• composition of the ECF

• temperature of the ECF

• volume of the ECF

All organ systems help maintain homeostasis with the exception of…

reproductive system (reproductive function)

Negative feedback

• most common type of feedback

• reverses a stimulus to maintain stability

• helps keep the body in balance

Think about it like lab, the making of one enzyme, trigger the previous enzyme to stop

Positive feedback

• amplifies a stimulus to drive a process

• continues until the process is complete

• Ex: LH pathway

Polarity in terms of water

• water has covalent bonds, electron sharing that completes its outer shell

• water is polar: electrons don’t have an even distrbution around a molecule.

• Oxygen has a higher EN, pulling electrons

• polar molecules are hydrophilic

Non-polar molecules

Molecule that has an even distribution of electrical charge (aroms shared equally.

• hydrophobic

4 main types of large biological macromolecules

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic acids

Carbohydrates

• called sugars/starches

• polar and dissolve easily in water

• polar because of hydroxyl group

Monosaccarides

Simple sugars; most common glucose

Glucose is

used by cells to generate ATP in cellular respiration

Disaccaride

two monosaccharides covalently bonded together

Sucrose (table sugar)

combines glucose and fructose

Lactose (milk sugar)

combines glucose and galactose

Polysaccharides

covalently bonded polymers of monosaccharide unites

Lipids

• “fats”

• nonpolar and insoluble (NP because they are made up mostly of long chains of C-H connected by nonpolar covalent bonds)

• Hydrophobic (some lipids are amphipathic)

Phospholipids structure

is hydrophilic, polar head and hydrophobic, non-polar tails

Types of lipids

1. Triglyceride

2. phospholipids

3. Steroids

Triglyceride

• considered fats

• single glycerol molecule and three fatty acid molecules

• most common lipid type

Phospholipids

• amphipathic molecules: hydrophilic head and two hydrophobic tails

• all cells have plasma membranes made up of these

Steroids

Cholesterol is the most common steroid and the starting point for the production of all steroids

Proteins

• polymers of amino acids

Amino acid structure

• composed of central C, amino group, carboxyl group, hydrogen group and an R-group (side chain)

• R group affects the amino acid function

• amino acids joined by peptide bonds and form polypeptides

• all polypeptides are made up of the same 20 AA’s

Primary Structure

the sequence of amino acids linked by peptide bonds

Secondary structure

the initial folding of the sequence of amino acids, caused by hydrogen bonding

• alpha helices and beta-pleated sheets

Tertiary structure

further folding caused by interactions between the R groups. 3D

Quaternary structure

the most complex structure that only exists in proteins with multiple polypeptide chains that interact with one another

Fibrous proteins

function in structure or contraction. Ex: collagen ; collagen fibers provide tensile strength to stop breakage when skin and other parts are pulled

Globular proteins

coiled, folded structures with many functions as enzymes, hormones, receptors and carrier proteins

Nucleotides function

transfer energy, provide intercellular signaling, and form genetic material

Nucleotide strucuture

nitrogenous base, 5- Carbon carbohydrate, and a phosphate group

What are the bonds between nucleotides?

Hydrogen bonds

Polar molecules contain

negative charged phosphate group and a sugar-phosphate backbone that interacts with water

Pyrimidine

One ring structure; Cystosine and thymine

Purine

Two ring structure; Adenine and guanine

mRNA (messenger RNA)

translated at the ribosome and determines the amino acid sequence in polypeptides

rRNA (ribosomal RNA)

component of ribosomes and catalyzes peptide bond formation

tRNA (Transfer RNA)

binds to mRNA sequences, brining specific amino acids ot the growing polypeptide chain

3 main components of a cell

Plasma Membrane, Cytosol, and Nucleus

What is the cytosol made of?

(intracellular fluid within the cell)

• extracellular fluid - fluid outside the cell

• cytoplasm - space inside the cell excluding the nucleus

• cytosol - intracellular fluid

• organelles - various functions carried out

Fluid mosaic model

Current theory of membrane structure:

• fluid = dynamic/moving

• mosaic = many parts

What are cell membranes made up of?

• 2 layers of phospholipids with proteins embedded

• phospholipids are amphipathic

• no polar molescules can move past the fatty acid tails

Cholesterol - function in the cell membrane

• embedded in the core of the membrane

• increase fluidity

• decrease membrane permeability

Integral membrane protein - function

• embedded and stuck into plasma membrane

• permanent

• function: receptors, pores (H2O) channels, enzymes

• (transmembrane - span across the whole membrane and peripheral - not permanently associated)

Membrane Carbohydrates

• covalently bond to integral proteins or phospholipids

• important for cell recognition with immune cell

Glycolipids

• amphipathic molecules with sugar molecule attached to phosphate group of phospholipid

• Outer sufrace

• used for cellular adhesion, recognition and growth

Rough ER

Ribosomes for protein synthesis

Smooth ER

Does not have ribosomes; calcium is stored and lipids, steroids, and triglycerides are made

Golgi apparatus

packing and shipping center; proteins travel through cisternae (received @ cis face and shipped off at trans face)

Mitochondria

produces ATP, with double membranes

• folded inner membranes called cristae that increase SA and help produce more ATP

Lysosomes

contain digestive enzymes. Autophagy: cells digest their own components

Peroxisomes

digest toxic substances and produce hydrogen peroxide (H2O2). They contian catalase to break down hydrogen peroxide.

Microfilaments

smallest diameter

• movement

• actin and microvilli increase surface area

intermediate filaments

• myosin nad keratin

• anchoring

Microtubules

• largest in diameter

• hollow tube that form cilia and flagella for movement

Tight junctions

seal cells so no fluids leak between them

Desmosomes

Anchor cells like a zipper and resist stretching

• cadherin proteins are major components

• tissues that are constantly under stress like heart or skin

Gap junctions

provide tunnels between adjacent cells connected by membrane protein called connexons

Diffusion

nonpolar molecules driven by a concentration gradient

carrier proteins

large polar molecules

Channels

free passage of water and ions into and out of the cell

Vesicles

membrane - bound sacs that transport macromolecules. endo and exocytosis

Direct communication

gap junctions

indirect communication

chemcial messengers such as hormones

Gene

a segment of DNA with a specific order of linked nucleotides that code from a specific protein

Genome

the collection of genes in a given species

protein synthesis general steps

1. DNA is transcribed

2. mRNA moves from the nucleus to the cytoplasm

3. mRNA is translated by ribosomes

Transcription

mRNA is transcribed from its complementary strand

• pre-mRNA undergoes post transcriptional modifications in the nucleus before it moves to the cytoplasm for translation

• This includes the addition of poly-A tail, 5’ cap, and or splicing of exons

Translation steps

Process in which polypeptides are synthesized using mRNA codons in the ribosomes of the cytoplasm

1.Initiation: ribosomal subunits bind, initiation codon is

aligned in the A site

2. Elongation: start codon moves to the P site, additional

codon binds to the A site, peptide bond forms, codon

moves to the E site (repeat)

3. Termination: stop codon binds and protein synthesis ends

Start codon

AUG

Post-translational processing

• cleavage of amino acids

• packaging in the golgi body

• addition of chemical groups (carbohydrates or lipids)

• destination: vesicles, membrane, cytosol

DNA replication

• semi-conservative process

1.Helicase unwinds DNA

2. DNA Polymerase catalyzes the reaction

that adds complementary base pairs to the

strand

a. Leading Strand and Lagging Strand

3. DNA ligase links fragments together on the

lagging strand

Cell life cycle

1. Interphase: G0, G1, S, G2

2. M-phase: cell division

a. Mitosis

b. Meiosis

Metabolism

sum of all chemical reactions that occur in cells

• mass of reactants = mass of products

Catabolism

Breaks down

ex: proteins - amino acids

Anabolism

produce larger molecules

• nucleotides - nucleic acid

Hydrolysis

split larger molecules with water into smaller molecules

• catabolic

• water reactant

condensation

• anabolic

• water product

Phosphorylation

add phosphate (Pi)

Dephosphorylation

remove phosphate (Pi)