Exam (elaborations) Cell Biology

BIO 253 – FINAL EXAM QUESTIONS WITH VERIFIED
ANSWERS

Negative feedback
- Most common in body
- Effectors return conditions to normal
- Shuts off when normal state is reached, counters/corrects something
- Long-lived
- Think furnace thermostat
- BP, glucose, temp, hormones
Positive feedback
- Change is intensified, keeps stimulating until homeostasis is reached
- Can produce unstable conditions in the beginning
- Short-lived
- Labor, blood clotting, sneezing
Anatomical position
To stand erect facing forward with arms at the sides and palms of the hands turned
forward with feet flat on the floor
Anterior/Ventral
Front
Posterior/Dorsal
Back
Superior
Top
Inferior
Bottom
Medial
Middle
Lateral
Away from the midline
Bilateral
Both sides
Ipsilateral
Same side
Contralateral
Opposite side
Proximal
Closer to the point of attachment
Distal
Away from the point of attachment
Superficial
Near the surface
Deep
Away from the surface
Sagittal plane

,Divides body into left and right
Transverse plane
Divides body into top and bottom
Coronal plane
Divides body into front and back
Abdominal regions: both upper right and left
Hypochondriac
Abdominal regions: upper middle
Epigastric
Abdominal regions: middle right and left
Lateral
Abdominal regions: middle
Umbilical
Abdominal regions: lower right and left
Inguinal
Abdominal regions: lower middle
Pelvic
Cation
- Positively charged
- Loses electron to become stable
Anion
- Negatively charged
- Gains electron to become stable
Ionic bond
- Strong
- Will lose or gain electrons
- Salt
Covalent bond
- Strong
- Shares electrons
- Polar, nonpolar
- Gases, H2O
Organic molecules
- C & H are directly attached
- Carbs, lipids, protein, nucleic acids
Inorganic molecules
- Does not have C & H both
- HCO3 (Bicarb), H2O, O2, CO2, Salt
Carbs
- Glucose
- Main source of energy
Lipids
- Fatty acids
- Triglycerides
Proteins

,- Amino acids
- Last resort for energy
- Peptide bonds (weak)
Nucleic acids
- Nucleotides
- DNA, RNA
Cell membrane
- Selectively permeable
- Made from lipids & proteins
- Tails in, heads out of phospholipid bilayer
Cytoplasm
- Cytosol
- Organelles
Nucleus
- Control center
- DNA & RNA made
Golgi apparatus
- Stacks of vesicles
- UPS / transport center
- Refines, packages, delivers proteins made in RER
Nucleolus
- Makes ribosomes
RER
- Next to nucleus & rough
- Makes proteins
Ribosomes
- Attached to RER
- Site of protein synthesis
SER
- Smooth & shiny
- Makes lipids & steroids
Mitochondria
- Makes ATP
- Powerhouse
Lysosomes
- Protection (Lysol)
- Contains digestive enzymes
Centrosomes
- Always in pairs
- Needed for mitosis
- Sac contains pairs of centrioles
Active transport
- Uses ATP
- Low to high concentration
- Endocytosis, exocytosis
Passive transport

, - Does not use ATP, O2
- Osmosis, diffusion, facilitated diffusion, filtration
Hypotonic
Cells shrink
Hypertonic
Cells swell
Cell cycle
- Interphase
- Mitosis
- Cytokinesis
Interphase
- G1: duplication of organelles
- S: duplication of DNA
- G2: double check of all processes
Mitosis
- Regen of somatic cells w/ division of the nucleus
- Prophase
- Metaphase
- Anaphase
- Telophase
Prophase
- Chromosomes appear
- Centrioles move to opposites of the cell
- Nucleus disappears
Metaphase
Chromosomes line up in the middle of the cell
Anaphase
- Centromere splits
- Sister chromatids move to opposite sides of the cell
- Cleavage furrow begins
Telophase
- 2 nuclei
- Prominent cleavage furrow
Skin
- Largest organ
- Stratified squamous
- Prevent H2O loss
- 1st line of defense (intact)
- Sensation
- Regulate body temperature w/ blood vessels & sweat
- Excrete waste
- Vitamin D for Ca absorption
- Cutaneous membrane
- Hair, nails, skin, glands, nerves
- Layers: Epidermis, dermis, SQ (hypodermis)
Epidermis