A phospholipid consists of...

A head: glycerol + phosphate

Tails: 2 fatty acids

Hydrophilic

Water-loving

Hydrophobic

Water-fearing

What is the function of cholesterol?

To stiffen the cell membrane and make it more rigid

Integral Proteins

Embedded; span membrane

Peripheral Membrane

Loosely associated with the outer or inner surface

Carbohydrates

Sugars associated with the outside of the membrane; face extracellular environment

Cell-to-Cell Adhesion/recognition

Fluid Mosaic Model of Membrane Structure

Diffusion

Movement of substances from high to low

Down Concentration Gradient

What kinds of molecules can exit and enter cells by diffusion?

small, hydrophobic

EXAMPLE: gases/lipids

Osmosis

diffusion of H2O through a membrane from an area of low solute (high H2O) to an area of high solute (high H2O).

Tonicity

relative solute concentration of two solutes

Hypotonic:

Low solutes; cell will swell and explode

Hypertonic:

High solutes; cell will shrivel (CRENATION)

Isotonic:

Same solutes: cell will maintain a healthy shape

Plasmolysis

Cell membrane withdraws from the cell wall

Turgor Pressure

H20 pushing outward against cell wall (Hypotonic)

DO NOT BURST

Facilitated Diffusion

Passive transport aided by integral membrane proteins

Channel Proteins

integral membrane protein with a passageway for substances to pass (do not change shape)

EXAMPLE: substances that cannot penetrate the bilayer (charged atoms)

Carrier Proteins

Integral membrane proteins that can change shape

EXAMPLES: sugars; amino acids

Substance binds carrier; carrier changes shape; substance exposed to inside of the cell (continues to equilibrium

Active Transport:

Movement of a substance through a membrane from an area of LOW concentration to HIGH concentration (uphill)

Requires energy; requires integral membrane protein

1/3 of your energy is needed to run pumps!

Endocytosis:

uptake of molecules and particulate matter by forming new vesicles from the plasma membrane

Phagocytosis

"cell eating" LARGE particles

Extensions of the cytoplasm surround the particle to form a vesicle

Pinocytosis

"cell drinking" INVAGINATION

NO psuedopods; membrane pinches to form a vesicle

Receptor Mediated

Substance first binds to a membrane protein receptor

highly selective (LDL: Bad Cholesterol)

Exocytosis

move substances out; secretion of large molecules from the cell by the fusion of vesicles with the plasma membrane

secretory pathway

ACTIVE transport

Metabolism

total of all chemical reactions in a cell

Anabolic

building reactions (monomers to polymers)

require energy

Catabolic

break down (polymers to momomers)

release energy

Endergonic

requires energy (monkey climbing)

Exergonic

releases energy (monkey dropping coconut)

Energy Coupling

Cells couple energy releasing reactions to energy consuming reactions

ATP Hydrolysis

exergonic

release of energy with mechanical energy

Add water to cleave off last phosphate

How is ATP hydrolysis coupled to processes that require energy?

endergonic reactions

ATP------> ADP + P +Energy

Enzymes

catalysts; speed up reactions

ACTIVATION ENERGY

Active Site

Groove or fold in enzyme where substrate binds

Induced Fit

Both enzyme and substrate change their shape

What happens when substrate levels are high and all active sights are occupied

enzyme is saturated and rates level off (Plateau)

REDOX (Oxidation and Reduction Reactions

transfer of electrons from one reactant to another

Oxidation

during catabolism of bonds of food; electrons are released

Delivery to FEA

Fuel e- +Y------> product + Ye-

Y becomes reduced

Reduction

gained electron

Aerobic Respiration

Break down of bonds of our food and release electrons and put them on O2 (final electron acceptor)

Glucose Catabolism

C6H12O6 + 6O2-----------> CO2 + 6H2O + Energy

Glycolysis

Occurs in cytosol

Conversion of glucose to 2 pyruvates

e- are not directly added to oxygen

e- are added to NAD (intermediate electron acceptor) to make NADH

ATP produced by substrate level phosphorylation (2 ATP)

Products: 2 ATP, 2 Pyruvates, 2 NADH

Pyruvate Oxidation

Occurs in matrix of mitochondria

Conversion of 2 pyruvates to acetyl CoA (2)

electrons released from pyruvate during oxidation are added to NAD

No ATP is produced

Products are: 2 NADH, 2 Co2, 2 Acetyl CoA

Kreb's Cycle

Occurs in matrix of the mitochondria

Conversion of 2 acetyl CoA to CO2

Electrons are added to NAD and FAD

ATP is produced by substrate level phosphorylation

Electron Transport Chain

Occurs on CRISTAE: folds of inner membrane of mitochondria

series of electron carriers in the cristae; e- from NADH + FADH2 that were generated in the Kreb's cycle, pyruvate oxidation, and glycolysis are added to the e- carriers here

30-32 ATP

Oxidative Phosphorylation

how electron transport and energy release by the electron transport chain is coupled to ATP formation

Steps of Oxidative Phosphorylation/ETC

1.) electrons pass down the ETC to o2 to form water

2.) this causes H+ ions to be pumped from the matrix of the mitochondria to the intermembrane space. Hydrogen ions accumulate here.

3.) Chemiosmosis----> H+ move down their concentration gradient through ATP synthase, a protein complex in the inner membrane that acts as a "water wheel" or a molecular rotary engine. When it spins, this activates catalytic sites on ATP synthase that bind ADP and P to form ATP

Advantage of Fermentation

regenerate NAD that can be used in glycolysis for ATP production

Somatic Cell

body cell; all cells in body except for eggs and sperm

Karyotype

Picture of chromosomes

Diploid

2 sets of chromosomes (somatic cells)

Homologous chromosomes

same length, centromere position, and carry genes controlling the same traits

Haploid

One kind of chromosome (1 set)

Meiosis

Reduces Chromosome number; occurs in the gonads; starts with diploid germline cell

Prophase 1

Nuclear membrane and nucleolus disappear

centrioles separate and spindle fibers form

chromosomes condense

homologous chromosomes pair up (SYNAPSIS)

Crossing Over

Individual chromosomes that carry information from both parents

source of genetic variation

Chromatid breaks and exchanges with nonsister chromatid

Metaphase 1

Homologous pairs line up on the equator

Anaphase 1

homologous chromosomes separate

Telophase 1

nuclear membrane reforms

spindle fibers disappear

DNA uncoil

END OF MEIOSIS 1

2 haploid cells; reduction division

diploid into haploid

Interphase 2 (or interkinesis)

NO DNA REPLICATION

Prophase 2

Typical prophase events

Metaphase 2

chromosomes line up on the equator

Anaphase 2

Split centromeres and go to opposite poles

Telophase 2

Typical telophase events; cell splits by means of cytokinesis

END OF MEIOSIS 2

4 HAPLOID cells

Independent Assortment

Independent orientation of homologous chromosomes at equator in metaphase 1

Monohybrid Cross

Following of one trait (height)

True Breeding

Plants that produce offspring of the same variety when they self-pollinate

Gene

unit of heredity that is transferred or passed down from a parent to their offspring and determines some characteristics of that offspring

Allele

alternate versions of a gene on the same locus

Genotype

Genetic traits; set of genes in DNA responsible for a trait

Phenotype

Physical traits; physical expression of a gene

Homozygous/Heterozygous

Same: homo

Different: hetero

Dominant Allele

ALWAYS shows up in an organism; captial representation; "stronger" gene

Recessive allele

"hidden" when the dominant allele is present; "weaker" gene represented by a lowercase letter

P Generation

Parent Generation

F1 Generation

Generation resulting immediately from a cross of the P1 generation

F2 Generation

Offspring from the interbreeding of F1 generation

Test Cross

Used to determine if a group exhibiting a dominant trait is heterozygous or homozygous

Principle of Segregation

The two alleles for a heritable characteristic separate during the formation of gametes in meiosis and end up in different gametes at the end

DiHybrid Cross

heterozygous for 2 characteristics

Principle of Independent Assortment

Each pair of alleles segregates independently of each other pair of alleles during gamete formation if the genes are located on different chromosomes

Incomplete Dominance

Not all alleles are fully dominant or recessive

Heterozygous individual: phenotype is intermediate between the parents

Multiple Alleles

genes with more than two alleles in the population

example: blood type

Alleles and Antigens of Blood

IA ------> A antigen

IB-------> B antigen

i----------> no antigen

Pleiotropy

one gene has multiple affects on phenotype

example: sickle cell allele

Polygenic Inheritance

Many genes- One trait

Few phenotypes result from one gene

Examples: hair color; skin tone; height

Multi-Factorial

Traits that depend on multiple genes combined with environmental influences

Y Chromosome

SRY Gene (sex determining region on the Y chromosome) triggers the development of testes

Who is more likely to get a sex-linked disorder?

Males