ap bio fuzzy areas

why does oxygen consumption show metabolism

• Measure how much O₂ an organism uses per unit time

• Higher O₂ use = higher cellular respiration = higher metabolic rate

👉 Why it works:

• Aerobic respiration requires oxygen to make ATP

why does CO2 production show metabolism

• Measure how much CO₂ is released per unit time

• More CO₂ = more respiration happening

Why does measuring body heat output show metabolism

Metabolism = chemical reactions → releases heat

Why does heat increase metabolism

• enzyme activity increases (to a point)

• respiration increases

• metabolic rate increases

Metabolism

all chemical reactions in the body

It includes:

• building molecules (anabolism)

• breaking molecules down (catabolism)

• making ATP (cellular respiration is a big part of this)

• DNA/protein synthesis

• active transport, etc.

Metabolic rate

how fast those reactions are happening

So it’s:

the rate (speed) at which energy is being used / reactions are occurring

Think of ATP like electricity in metabolism:

• More respiration = more electricity generated

• Not every device runs faster

• But more devices can run at once

What is surface area to volume ratio?

The amount of surface available for exchange compared to the amount of internal volume that needs resources.

What happens to SA:V ratio as organisms get larger?

It decreases because volume increases faster than surface area.

Why does a higher SA:V ratio increase exchange with the environment?

Because more surface is available per unit of volume, allowing more diffusion per unit time and shorter diffusion distances.

Why do small organisms have higher metabolic rates per unit mass?

a greater proportion of their body is exposed to the environment relative to their heat-storing volume.

• small organisms must produce heat faster

• which requires:

  • higher cellular respiration rate

  • higher metabolic rate per unit mass

cyanobacteria with thylakoids are now _____________ in eukaryotes, so there was compartments even in prokaryotes

chloroplasts

what is the endomembrane system made of

nuclear membrane, rough er, smooth er, vesicles, lysosomes, golgi complex

The endomembrane system is dynamic because its components are connected through continuous or vesicle-mediated membrane flow, allowing membranes and their associated proteins to be modified, transported, and recycled between the nuclear envelope, endoplasmic reticulum, Golgi apparatus, and plasma membrane.

transcription factors enter the nucleus through

nuclear pores

sites or rRNA from left to right

E, P, A

when do ribosomes go to rough er

when protein is destined for membrane, golgi, lysosome, other organelles, or export

chloroplast and mitochondria both have

own circular DNA (chromosome), bacterial ribosomes to make own proteins, double membrane (outside was the vesicle from the eukaryote’s plasma membrane)

smooth er has

enzymes

smooth er

detoxifying toxins into soluble form, lipid synthesis, carb breakdown and synthesis

golgi

receives vesicles from rough and smooth er and chemically modifies contents

packs into vesicles

lysosomes are only in

animal cells

cytoskeleton

dynamic network of protein fibers

enables cell to move membrane

enable cells to move materials and organelles

cellulose is a key component in

water conducting tubes in plant stems (xylem)

the phospholipid bilayer is stabilized by weak bonds between tails called

vander wells

what can go through membrane easily

oxygen, nitrogen, carbon dioxide

facilitated diffusion

facilitated down gradient, using kinetic energy from diffusing molecules

diffusion occurs because kinetic energy in higher concentration

• random motion

• statistical imbalance

• net movement emerges automatically

does exocytosis need input of energy to occur

Yes, exocytosis requires energy because ATP is used to transport vesicles along the cytoskeleton and to facilitate membrane docking and fusion with the plasma membrane.

1. Neurotransmitter binds receptor

2. Ion channels open

3. Small voltage change (EPSP/IPSP)

4. These sum together

5. If threshold reached → voltage-gated channels open

6. Action potential starts

hypotonic

more water, less solute

hypertonic

less water, more solute

water diffuses from

hypotonic (more water, less solute) to hypertonic (less water, more solute)

osmoregulate

regulate osmotic balance

how does more solute in a solution effect water potential

decreases it

water moves from high water potential to low water potential. explain

molarity in solution decreases water potential. water moves from hypo to hyper, so it moves to more solute which makes water potential negative. pressure in a solution increases water potential. water moves to lower water potential, away from this pressure.

Describe what would happen if you placed a plant cell in a 0.0 M solution.

a) The cell would lyse

b) The cell would be turgid

c) The cell would plasmolyze

d) The cell would be flaccid

plasmolyze and pull away from cell wall

• In liquid water, hydrogen bonds are constantly breaking and reforming

• In ice, they become more fixed and organized

in evaporation, what happens to bonds

hydrogen bonds break and the water molecules have kinetic energy and separate far apart like gas

When KE increases (heating):

• molecules move faster

• collisions become stronger

• eventually they break intermolecular hydrogen bonds

As kinetic energy increases, water molecules move faster and eventually overcome hydrogen bonds between molecules, allowing them to separate into the gas phase while remaining H₂O.

secondary structure of protein

percent change is

( final - initial ) / initial x 100

Why do metabolic pathways have many steps?

• Energy Efficiency: Releases energy in small, manageable amounts to capture it as ATP rather than losing it all as heat.

• Regulation: Creates multiple "checkpoints" where enzymes can speed up or slow down the process based on the cell's needs.

• Versatility: Produces intermediate molecules that can be siphoned off and used in other pathways (like building blocks for amino acids).

Compare intracellular vs membrane receptors (speed + regulation)

• Intracellular: slower response; directly regulate gene expression

• Membrane: faster response; indirectly regulate cell activity through signaling cascades (can eventually affect gene expression)

phosphotase

remove phosphate group

How is a protein kinase typically "turned on"?

Phosphorylation: An upstream enzyme (another kinase) attaches a phosphate group to a specific site on the kinase.

Once activated, what does a protein kinase do "over and over"?

• The Relay: It grabs fresh ATP from the cell, snips off the phosphate, and glues it onto a different target protein (often another kinase).

• Signal Amplification: A single active kinase can catalyze this reaction hundreds of times, activating a massive "army" of downstream proteins from just one initial signal.

What are the 3 primary ways a phosphatase is activated?

• Negative Feedback: A downstream kinase phosphorylates the phosphatase to trigger a shutdown.

• Ion Binding: Increased levels of Calcium (\(Ca^{2+}\)) bind to the enzyme to "toggle" it on.

• Recruitment: The phosphatase is physically moved (localized) to the area where the active kinases are.

Intracellular signaling is slower because it involves changes in gene expression, requiring transcription and translation, whereas membrane signaling modifies existing proteins and produces a faster response.

meiosis 1 nondisjunction result

50% of the gametes are normal, 25% have an extra chromosome, and 25% are missing one.

meiosis 2 nondisjunction result

Sister Chromatids

2 normal gametes, 2 abnormal gametes.

why do a testcross

determining if a parent is homozygous recessive or heterozygous. if one of the kids is recessive, then they are hetero, if all of the kids are dominant, they are homozygous dominant.

where is the tata box

In eukaryotes, many promoters contain a famous sequence called the TATA box (literally a string of Ts and As), which is easy for proteins to recognize and pull apart because A-T bonds are weaker than G-C bonds.

describe the steps of rna transcription

• Recognition: Transcription factors (helper proteins) bind to the promoter on the DNA.

• Binding: RNA Polymerase attaches to the promoter/transcription factor complex.

• Initiation: The DNA double helix is unzipped at the promoter site.

• Elongation: RNA Polymerase moves away from the promoter and down the gene to start building the RNA strand.

what happens in rna processing in eukaryotes

• introns removed (splicing)

• exons kept

• 5’ cap + poly-A tail