WEEK 1/ QUIZ 1 cell bio/ biochem

Is intra or extra cellular the majority of total body water

Intracellular (inside the cells)

What is in extracellular fluids

Interstitial fluids and blood

Properties of water

1. Polar

2. Solvent for inorganic salts

3. Solvent for polar organic

4. Intermolecular bonds

A buffer is comprised of

A weak acid and its conjugate base

Kidneys excrete

H+ as NH4+ and form bicarbonate (a buffer)

Lungs excrete

CO2, which lowers carbonic acid

Symptoms of acidosis

High H+, high RR, low BP, vasodilation, fatigue, coma

Symptoms of alkalosis

Low H+, low RR, high HR, vasoconstriction, hypoxemia, seizures → Ca2+ imbalance

Maple Syrup Urine Disease

Branched chain amino acids (Ile, Leu, Val) not broken down properly (deficiency of dehydrogenase)

Phenylalanine

Breaks down into tyrosine, otherwise PKU (phenylketonuria)

Tryptophan

Serotonin

Glycine

Smallest R group, collagen is Gly-X-Y

Osteogenesis imperfecta

An amino acid replaces glycine in collagen

Proline

Unique R group, kinky

Methionine

Sulfur, serves as methyl donor

Cysteine

Disulfide bonds are very strong (also has a Sulfur)

Phosphorylation of OH- groups

Ser, Thr, and Tyr

Participate in N/O glycosidic bonds

Asn, Ser, and Thr

Histidine

Histamine (gastric acid, allergies, inflammation)

Tyrosine

Catecholamines (dopamine, epi, norepinephrine)

Peptide bonds are between

Carboxyl of one and amino of other (O-N)

Primary protein structure

N→C covalent polar bonds

Secondary protein structure

Alpha helix or beta sheets

• possible bc of polar peptide bonds

• Hydrogen bonds

Tertiary protein structure

R groups stabilize disulfide bonds, hydrophobic bonds, hydrogen bonds, and ionic bonds

Quaternary protein structure

Only for proteins with more than 1 polypeptide (hydrophobic, hydrogen, ionic)

Osteogenesis imperfect type 1

Less severe, normal collagen structure, not enough collagen

Osteogenesis imperfect type 2

Usually fatal, glycine replaced with bulky R, collagen structure is disrupted

Sickle cell anemia

Glutamate replaced by valine

Glycocalyx

Important for cell-cell recognition (ABO)

Types of passive transport

Simple diffusion, facilitative diffusion, gated channels

Active transport

Primary- ATP used directly

Secondary- uses established gradient from ^

Vesicular transport

Membrane encloses (endo/ exocytosis)

Receptor mediated endocytosis

Molecules binds to receptor, endocytosis

All organelles

Are bound by membranes and anchored to cytoskeleton

Nucleus

Houses chromosomes, enzymes, and transcription factors

Nuclear lamina

LAMINA→ protein network for nuclear stability (laminopathies)

Hutchinson-Gilford progeria syndrome

Mutation in Lamina A gene → accelerated aging

Nucleolus

No membrane, enlarged in malignant crlls

Huntingtons and Alzheimer’s

Abnormal nucleolus (abnormalities of proteins in neuronal cells)

Ribosome

Site of protein synthesis

Endoplasmic reticulum

Tubules (cisternae) Attached to our layer of nuclear envelope

Rough ER

Ribosomes on surface, synthesizes proteins for SECRETION (found in secretory organs)

Cytosolic proteins

Synthesized in free ribosomes

Smooth ER

Site of lipid synthesis, lipid metabolism, carbohydrate metabolism, and site of chemical detoxification

Von Gierke disease

Glucose-6-phosphorite deficiency → hypoglycemia

Sarcoplasmic reticulum

Modified smooth ER in muscles (store Ca2+ for contraction)

Mitochondria

Makes ATP, citric acid cycle, circular maternally inherited DNA

Red raggedy fibers

Abnormal mitochondria in muscles

Golgi complex

Cis golgi faces nucleus (receives vesicles), trans faces away (releases vesicles)

COP1 and COP 2

1: retrograde transport (back to nucleus) cis

2: anterograde transport (forward) cis

Clathrin

Golgi complex → lysosomes

I-Cell disease

Enzymes are secreted instead of sent to lysosomes → lysosomes cannot breakdown waste (Golgi complex issue)

Lysosomes

Destroys/ recycles waste

Digests using hydrolase

Acidic environment

Gaucher disease

Lysosomal storage disorder (deficiency of B-gluco, gluco accumulates)

Peroxisomes

Formed from ER, catabolizes substrates like branched chains + very long chains

Zellweger spectrum disorders

Defect in peroxisomes → cannot breakdown branched chain/ long chain fatty acids

Central dogma

DNA replication → RNA → protein

Purines

Adenine and guanine (2 rings)

Pyrimidines

Cytosine, uracil, thymine (1 ring)

A-T hydrogen bond number

2

G-C hydrogen bond number

3

Higher G-C content means

Higher Tm

What is inhibited by quinolones

DNA gyrase (top 2) → prokaryotic supercoiling

RNA uses uracil instead of

Thymine

mRNA

5’, 3’ poly A tail, coding region

rRNA

Combine with proteins to make ribosomes

tRNA

Covalent links to ONE amino acid, cloverleaf structure