ALL UNITS (1-9) Anatomy and Physiology 12

Covers: Units 1-5

Homeostasis definition

The process by which living organisms regulate their internal environment to maintain stable, constant conditions despite external changes. This includes regulation of temperature, pH, and electrolyte balance.

The 4 mechanisms of homeostasis

1. A change (stimulus) occurs (anything that requires a cell to react)

2. Receptors detect the stimulus and alert the relevant control center

3. A control center which has a set point the particular factor should be at receives the signal from its receptors and sends a command to an effector

4. An effector is a physical change agent (e.g muscles, glands, fluids), it acts on the impulse from the control center and elicits a response to counteract the stimulus and return the body to homeostasis

‘SRCE’

Negative Feedback Definition

A process by which the body returns to a state of homeostasis. It involves receptors detecting changes, a control center processing the information, and effectors implementing responses to maintain homeostasis.

Positive Feedback Definition

The opposite of negative feedback- instead of returning to normalcy, a positive feedback loop further stimulates the regulatory center to continue producing the response (NORMAL CONDITION IS NOT REACHED)

*Know childbirth example

Covalent Bond Definition

The equal sharing of electron between atoms to form a stable molecule

Ionic Bond

Unequal sharing of electron between atoms resulting in charged ions

Polar covalent Definition

Involves the unequal sharing of electrons resulting in a DIPOLE

**Water is this type of molecule

*Dipole: a molecule with a slightly positive end and a slightly negative end

How does water’s polar nature cause water molecules to interact with each other?

Name of this bond?

Causes water molecules to be loosely attracted to each other- the negative charge on one molecules oxygen attracts the positive charge on another water molecule’s hydrogen atom

Produces a weak bond called a hydrogen bond, can bond with up to 4 other water molecules

5 important properties of water + example of each in the body/nature

*Focus on 1, 2, 5 as these relate to the human body

1. Universal Solvent: Water dissolves the most substances of any liquid

   Ex: Important in the blood as it helps transport dissolved substances throughout the body

2. High Heat of Evaporation: Water can absorb a lot of heat while only rising in temperature a small amount (vice versa also releases heat slowly).

   Ex: Body systems are mainly water therefore bodies tend to stay at a relatively constant temp

3. Density: Liquid water is denser than ice (water expands when it solidifies)

   Ex: Means ice floats so that water bodies never freeze all the way over allowing aquatic ecosystems to survive cold

4. Transparent: Light can penetrate through

   Ex: Allows aquatic plants to photosynthesize

5. Cohesive and Adhesive: Cohesion means water molecules stick to each other, Adhesion means water molecules stick to other surfaces

   Ex: Cohesion: High surface tension, aids in transport of water against gravity

   Ex: Adhesion: Water clings to the walls of blood vessels

4 Important functions of water in the human body

1. Universal Solvent: Water dissolves substances which aids in their transport through the body via the blood

2. High Heat of Evaporation: Helps bodies maintain a relatively stable internal temperature (homeostasis)

3. Necessary component for hydrolytic (hydrolysis) reactions to occur

4. Provides lubrication to help with movement (e.g. blinking)De

Buffer Definition

Resist large changes in pH despite the addition of H+ or OH- by accepting excess H+ or donating H+ to maintain a constant pH

Why are buffers important in the body?

Enzymes which control the chemical reactions of the body can only function at a certain pH

Monomer Definition

A single unit of a biomolecule- the building blocks of polymers

Polymer Definition

Larger molecule made by joining monomers together

Dehydration Synthesis Definition

A synthesis reactions that joins monomers to form a polymer by removing water

Hydrolysis Definition

A degradation reaction that breaks apart a polymer into its monomers by adding water

3 Groups of carbohydrates

1. monosaccharides aka simple sugars (monomers)

2. disaccharides (dimers)

3. polysaccharides (polymers)

Elements in carbo hydrates + H to O ratio

Carbon, hydrogen, oxygen

H:O 2:1 (CH2O)

Carbohydrates provide us with:

short term energy

3 monosaccharides are + where they’re found

1. glucose (main sugar in blood)

   *recognize drawing!

2. fructose (found in fruits)

3. galactose (milk and milk products)

3 disaccharides + their building blocks

1. Maltose: glucose + glucose

2. Sucrose: fructose +glucose

3. Lactose: galactose + glucose

What are polysaccharides?

Long chains of glucose molecules

3 polysaccharides + where they’re found/function + how to recognize the molecule

1. Starch: storage for food in plants (few side chains)

2. Glycogen: storage for food in animals (many side chains)

3. Cellulose: found in cell walls of plants, gives them their structure (alternating linkage between sugars, no side chains)

Importance of Cellulose for humans

We can’t digest the special linkage, passes through digestive system as roughage for good health + colon cancer prevention

3 types of lipids

1. Neutral fats

2. phospholipids

3. steroids

   *we can metabolize and produce lipids

Elements in

Elements in lipids + H to O ratio

Carbon, hydrogen, and oxygen H:O greater than 2:1 (greater than ratio in carbohydrates)

What are fatty acids + where are they found

Non-polar chains of C and H with carboxylic end (COOH)

One of two building blocks of neutral fats

Saturated vs Unsaturated fatty acids

Saturated FAs: No double bonds, max hydrogen

Unsaturated FAs: Have double bonds between carbons, not max hydrogen

*for drawing just look for double line (double bond)

What is a Neutral fat? + 3 types

1 molecule of glycerol in combination with 1-3 FAs

1. Monoglyceride (1 FA attached to 1 glycerol)

2. Diglyceride (2 FAs attached to 1 glycerol)

3. Triglyceride (3 FAs attached to 1 glycerol)

   * Structure looks like a capital E

Function of Neutral fats

long term energy source, insulation, padding

*2nd most important energy molecule

What are phospholipids

A type of triglyceride where one of the 3 FAs is replaced with a phosphate and nitrogen group

*Therefore glycerol, 2 FAs, and a phosphate group are the building blocks

What is a special property of phospholipids?

The phosphate group is polar (head) and the FAs are non-polar meaning phospholipids can mix with both polar and non polar materials

Head is hydrophilic (water loving) tail is hydrophobic (water hating)

Why are phospholipids important in cells?

Main component of the cell membrane called phospholipid bilayer

*due to polar head, non polar tail

General structure of steroids + 3 examples

Non-polar ring structure (insoluble in water- reason they’re considered lipids)

Ex: Sex hormones, cholesterol, some ingredients in bile

What does cholesterol do? What happens if you have too much

Important part of the cell membrane + protective cover around nerve fibers

Too much leads to high blood pressure (fatty deposits in arteries, narrows passageway)

What does testosterone do?

Passes through cell membrane to combine with receptors in the cell to activate certain genes for protein synthesis

*Increase protein synthesis=better muscle development, why athletes want

Elements that make up proteins

Carbon, hydrogen, oxygen, nitrogen, and sulfur (sometimes phosphorus and iron)

Basic structure of a protein

Long chains of amino acids (called a polypeptide)

What are the different parts of an amino acid

amine group, carboxylic acid, central carbon bonded to hydrogen, radical (variable) group

How is a polypeptide formed? + name of the bonds

Amino acids are joined through dehydration synthesis and are held together by peptide bonds (between C and N)

*Order and combination determines type of protein

What are the 4 levels of protein structure + bonds that form (explain the first 3)

1. Primary Structure: a straight sequence of amino acids, bonded by peptide bonds

2. Secondary Structure: Long chain of amino acids twists into a spiral called an alpha helix, hydrogen bonds form between hydrogen of one AA and oxygen of another

3. Tertiary Structure: Alpha helix bends and folds into a globular molecule, when alpha helix is too long kinks form as not all AAs can fit this configuration, ionic, covalent, and/or hydrogen bonds form* (+sometimes sulfur. Usually occurs in enzymes- 3D shape=function

   *3rd level=3 types of bonds

4. Quaternary Structure

What causes a protein to denature and why?

Weak hydrogen and ionic bonds in tertiary structure are easily broken. pH change, heavy metals, or extreme temperature changes

4 key points about protein denaturation + result in human body

1. Enzyme looses its normal 3D shape, shape of its active site is changed

2. Can no longer bind to its substrate

3. Because of this can’t perform its normal function

4. No enzyme activity

   Results in disease or death

Function of enzymes + examples

Biological catalysts that speed up reactions, transport molecules, fight infection

Structurally: maintain connective tissues, keratin (protective layer in skin), collagen (major component of connective tissue), actin (involved in muscle contraction for movement)

What are the 2 building blocks of nucleic acids?

Polymers and nucleotides

What are the 3 components of nucleotides

A sugar, a phosphate group, and a nitrogenous base

*Know how to recognize/label structure

What are the 3 types of nucleotides?

DNA, RNA, ATP (Adenosine triphosphate)

Structure of ATP

An RNA nucleotide with an adenine base and 3 phosphate groups attached through high energy phosphate bonds

Function of ATP + How it structure gives it this function

Phosphate bonds are very rich in energy allowing cells to store energy as chemical energy through ATP. ATPase enzyme breaks one of the phosphate bonds to produce ADP and energy

*ATP is the energy currency of the cell

What 2 statements make up the Cell Theory + Scientists behind them

1. “The cell is the building block of all organisms” (Schleiden and Schwann- 1830s)

2. “Cells come from pre-existing cells” (Virchow- a few years later)

Key characteristics of prokaryotic cells

‘PRO’ = ‘NO’ nucleus (or other membrane bound organelles), have ribosomes, less efficient as reactions occur all over the cytoplasm

*Only Kingdom consisting of prokaryotic cells is the Monera

Key characteristics of Eukaryotic cells

‘EU’=’NU’ they do have a nucleus (plus other membrane bound and non membrane bound organelles that carry out a specific function)

*Kingdoms include: Plants, animals, fungi, protists

4 Key differences between plant and animal cells

1. Plant cells can be larger

2. Plant cells contain chloroplasts

3. Plant cells contain a large central vacuole

4. Plant cells have a cell wall

What are chloroplasts

Chloroplasts contain chlorophyll which absorbs sunlight so they can undergo photosynthesis and get energy

What is the cell wall

A rigid structure composed of fats and cellulose surrounding the cell membrane to provide structure and protection

What are vacuoles (plant cells)

Plant cells contain 1. It is large and liquid filled, and surrounded by a single membrane. Mainly serves as a space filler, but can also store nutrients and degrade waste

*Can occupy up to 90% of a cell’s volume

Nucleus structure

Largest organelle, surrounded by a double membrane (nuclear envelope). Nuclear envelope is porous to allow large molecules through

Nucleus Function

Control center for cell’s function + contains chromatin

Nucleolus function + location

rRNA is produced and stored, involved in interactions between the nucleus and cytoplasm

It is the dark region in the nucleoplasm

What is chromatin

Hereditary material of the cell, condenses to form chromosomes during cell division, made up of protein and DNA

What are chromosomes

Condensed chromatin, contain genes (hereditary info) rod shaped, located in the nucleus during cell division

*Human cells have 46

What is the cytoplasm

Contains and supports all cell organelles, can change between gel and liquid with addition of heat

Cell membrane composition + function + key features

Made up of proteins and phospholipid, located around the outside of the cell, acts as a ‘skin’ around the cell contents, it is selectively permeable to allow movement of materials in and out of the cell

Smooth ER structure + location

Interconnected flattened tubes/sac/canals

Begins at the nuclear envelope and branches through the cytoplasm to the cell membrane

‘CANALS are the main transport through ketterdam therefore CANALS of the SER go from nuclear envelop to cell membrane’

Smooth ER function + type of cell it is abundant in

produce lipids (SMOOTH like BUTTER) and move them throughout the cell- sections can break off (blebbing) to produce membrane bound sacs (vesicles) containing lipids

*Cells that produce steroids have abundant SER (makes sense steroids are lipids)

*Liver cells SERs have additional enzymes that help to detoxify

What is the rough ER + what type of cell is it abundant in

Same as SER, but with attached ribosomes (‘r’ in rough=’ribosomes’)

Abundant in cells that produce large amounts of protein

Golgi Body structure

Stack of ~half a dozen flattened sacs

Golgi Body function + type of cell where it is abundant

Receives protein filled vesicles from ER, sorts, modifies, and repackages them in vesicles (manufacturing, warehousing, sorting, and shipping center of the cell)

(GOLGI BODY? You’ve got a GORGEOUS BODY thanks to all those PROTEIN SHAKE PRs YOU RECEIVE) (golgi body really be doing the most)

Abundant in cells specialized for secretion

Vacuole function

Storage for water, nutrients, and wastes

What are vesicles + how are they produced

Small vacuoles made by Golgi body/in-folding of the cell membrane, storage site for various kinds of molecules

What are lysosomes (+function) + where are they formed

Small vacuoles formed by the golgi body (double membrane), contain powerful hydrolytic enzymes for digesting substances entering the cell/organelles that are no longer of use

Ribosome composition and location

Contain rRNA and protein subunits, found in the RER and the cytoplasm

*Several ribosomes in a line producing the same protein= a polyribosmes

Ribosome function

Protein synthesis

Structure of the mitochondria

Double membrane bound, inner membranes loop back and fourth increasing surface area and producing shelf like structures (cristae)

Mitochondria function

The powerhouse of the cell- undergoes cellular respiration using glucose and oxygen to produce carbon dioxide, water and energy

Cytoskeleton structure + function

Composed of microfilaments and microtubules, provides internal structure + anchors organelles

Cillia composition + function

Hair like projections composed of microtubules, move like oars for locomotion in many unicellular organisms

Flagella structure and function

Longer than cilia- tail like and move like whips, for locomotion of organisms and gametes

What is the accepted theory for the cell membrane structure

Fluid Mosaic Model: Made up of a double layer of phospholipids with proteins scattered throughout

*Water travels through the pore formed by proteins, proteins have polar and non-polar ends

What are the 2 types of cell identification markers

1. Glycoproteins- protein + carbohydrate tail

2. Glycolipids- phospholipids + carbohydrate chain

Define:

1. Impermeable

2. Permeable

3. Semi-permeable

4. Selectively permeable

   Which describes cell membranes?

1. Nothing passes through

2. Most things pass through

3. Small molecules pass through, large can’t

4. only certain molecules (large or small) can pass through

   *Cell membranes are selectively permeable

What is diffusion + how is it facilitated

Movement of a solute from [high] to [low] until it is evenly distributed

No membrane, carrier, or ATP required

What is osmosis + how is it facilitated

Water moves from an area of [high] to [low] *across a membrane

No carrier or ATP required

*Solute is too big to pass through membrane so water moves across from [high water] to [low water]

Define hypertonic solutions + would a cell in this solution expand or crumple

The solution with the GREATEST amount of solute compared to another solution (its HYPER because there’s so much spazzy solute), cell would crumple because water goes to [higher] of solute outside the cell (crumple under the pressure of hyperness)

*tonicity refers to [solute] in a solution

Define Hypotonic solutions + would a cell in this solution expand or crumple

Solution with the LEAST amount of solute compared to another solution (HYPOthermia means you have LITTLE heat), cell would expand because water would flow into the [lower solute] in the cell (HYPnOtizes the water into coming in)

*Water always moves from Hypotonic solution to Hypertonic solution (Kids hyperness beats even hypnosis)

Define isotonic solutions + would a cell in this solution expand or crumple

Two solutions with the SAME [solute], (ISOmer means SAME element) cell would be normal, no net movement of water

What is facilitated/passive transport + how is it facilitated

Solutes move across a membrane from [high solute] to [low solute], requires help from a carrier molecule (protein), no ATP required (Facilitated = requires help from carrier molecule)

*Glucose enters a cell from the blood via facilitated transport

What is active transport + how is it facilitated

Solutes move from [low solute] to [high solute] across a membrane with the help of a carrier molecule (protein) and ATP (ACTIVity requires energy- makes sense since its moving agains the concentration gradient)

What determines surface area of a cell

Amount of cell membrane

What determines volume of a cell

size of the cell (#organelles)

Describe Surface area to volume ration for small cells vs. large cells + impact of this ratio on cell

Small cells: High SA:Volume ratio therefore they can supply organelles with enough nutrients/remove waste

Large cells: Low SA:Volume ratio therefore waste will build up and nutrients will run out

*Cells are limited in size and more active cells must be smaller- but folds are a sneaky way of increasing SA

6 Factors that affect diffusion + how

1. Temperature: Higher temperature = diffuse faster

2. Surface area: Larger SA = diffuse faster

3. Concentration gradient: Higher gradient = diffuse faster

4. Size of particle: = smaller particle = diffuse faster

5. Diffusion medium: Solid = slowest, liquid faster, gas = fastest

6. Movement of the medium: greater movement = diffuse faster (e.g air current/stirring)

Define endocytosis + what are the 2 types

process in which large molecules enter a cell (‘ENDO’ = ‘END UP’ inside the cell)

1. Phagocytosis: process in which pathogens (foreign whole cells or bacteria) are taken in (cell eating- PHAG rhymes with to-go BAG for dinner)

2. Pinocytosis: process in which liquids are taken in (cell drinking ‘PINOCOLADA’

Define exocytosis

process by which products/waste exit a cell

Structure of the purines + which bases are purines

Two carbon nitrogen ring, bases are adenine and guanine

(put TWO RINGS on it plus AGe appropriate=pure

Structure of the pyrimidines + which bases are pyrimidines

One nitrogen ring, bases are thymine and cytosine

In a DNA molecule, what makes up the ‘rungs’ what makes up the ‘backbone’

Complementary bases bond to make up the rungs, alternating deoxyribose sugar and phosphates make up the backbone

What are the complementary base pairings + # of hydrogen bonds involved

AT, 2 hydrogen bonds (ATINY amount of hydrogen bonds)

CG, 3 hydrogen bonds (3G internet)

*Number, order, and type of bonds determine the type of organism

4 steps in DNA replication + any enzymes involved in that step

1. DNA molecule is untwisted by enzymes, each side acts as a template *Enzyme helicase (helicopter unzips DNA) breaks weak hydrogen bonds between base pairs

2. Complementary nucleotides present in the nucleus move into place and pair with the bases on the exposed strands *Enzyme DNA polymerase (erases memories of old DNA strand by replacing new nucleotides) assists

3. Alternating sugar phosphate backbone is glued together (by the enzyme ligase (ligase give glue vibes) and adjacent nucleotides become joined together

4. 2 new IDENTICAL DNA strands wind back up in double helix shape