Bio exam lecture 2

Matter & Work:

Matter is anything with mass/volume; Work is the use of energy to move matter against a force.

Laws of Thermodynamics:

1st Law (Energy cannot be created/destroyed) and 2nd Law (Systems move toward Entropy, or disorder).

ATP (ADP):

The primary energy currency of the cell. ATP stores energy; ADP is the "uncharged" form.

Enzymes:

Proteins that act as biological catalysts to speed up chemical reactions.

Cellular Structure & Transport

• Eukaryote vs. Prokaryote:

• Eukaryotes have a Nucleus and membrane-bound organelles; Prokaryotes do not.

Organelles:

A specialized subunit within a cell that has a specific function, much like an organ in the human body (e.g., the heart or lungs).

Respiration (Cellular):

This is the process of breaking down Glucose (sugar) in the presence of oxygen to produce ATP (energy), water, and carbon dioxide.

Chloroplasts:

These are the specialized organelles in plant cells and algae that serve as the site of photosynthesis, capturing light energy to convert water and carbon dioxide into food (glucose).

E.R. (Smooth/Rough):

The Endoplasmic Reticulum is a continuous membrane system where the Rough E.R. (studded with ribosomes) handles protein synthesis, while the Smooth E.R. is responsible for lipid synthesis and detoxification.

Golgi:

• Often called the "post office" of the cell, the Golgi apparatus modifies, sorts, and packages proteins and lipids into vesicles for delivery to specific destinations

Ribosomes:

These small structures serve as the primary site of protein synthesis, where they translate genetic code into specific chains of amino acids.

Vacuoles/Vesicles:

These are membrane-bound sacs used for storage and transport; vacuoles often store water or nutrients (especially large in plants), while vesicles move materials between organelles or to the cell membrane.

Cell Wall:

Located outside the cell membrane, the cell wall is a rigid outer layer found in plants, fungi, and some prokaryotes that provides structural support and protection.

Cell Membrane:

A Fluid Mosaic Model made of Amphipathic Phospholipids (hydrophobic tails/hydrophilic heads).

Transport: * Passive (Diffusion/Osmosis):

Movement from high to low concentration without energy.

• Active: Requires ATP to move against concentration gradients.

• Vesicle Mediated: Endocytosis (in), Exocytosis (out), and Phagocytosis (engulfing particles).

Metabolism:

The sum of all chemical reactions (Anabolism builds up; Catabolism breaks down)

Photosynthesis:

Converting Sun light into Glucose.

Light Reactions:

Use Photosynthetic Pigments to capture energy.

Dark Reactions:

Fix carbon into sugar.

Respiration

Breaking down glucose for ATP.

Glycolysis

Initial breakdown of glucose.

Citric Acid Cycle

• Completes glucose breakdown

E.T.C. (Electron Transport Chain)

High-energy electrons create a massive ATP yield.

Aerobic vs. Anaerobic:

With vs. without oxygen.

Evolution

Change in allele frequencies in a population over time.

Natural Selection

• Individuals with higher Fitness survive and reproduce.

Speciation: Allopatric/ Sympatric

Speciation: The formation of new species, often via RIMs (Reproductive Isolating Mechanisms).

• Allopatric: Due to geographic isolation.

• Sympatric: Occurs in the same geographic area.

Connecting the Dots

The "Grand Connection" is Homeostasis. Cells use Energy (from Photosynthesis/Respiration) and Enzymes to power Active Transport and Metabolism. This allows them to maintain a stable internal environment despite the Entropy of the universe.

When environments change, Natural Selection acts on these survival traits. If populations become separated (Allopatric Speciation) or stop breeding (RIMs), Evolution creates new species.

Practice: Relating 5 Random Terms

Let's link: Chloroplasts, Entropy, Active Transport, Fitness, and Natural Selection.

• Chloroplasts capture solar energy to create order (glucose), fighting against Entropy.

• The cell uses that energy to power Active Transport, maintaining the specific ion balances needed for life.

• An organism that is highly efficient at these processes has higher Fitness in its environment.

• Over time, Natural Selection ensures that the genes for these efficient cellular processes are passed down to future generations.

Aerobic vs. Anaerobic and the Citric Acid Cycle.

• Aerobic Respiration: This happens inside the mitochondria because it requires oxygen to produce a high yield of ATP.

• The Citric Acid Cycle & E.T.C.: These specific "steps" of respiration mentioned in your notes take place within the different compartments of the mitochondrion (the matrix and the inner membrane).

lets link Mitochondria, ATP, Active Transport, Homeostasis, and Natural Selection.

• Mitochondria perform respiration to generate a constant supply of ATP.

• The cell uses that ATP as fuel to power Active Transport (moving molecules across the cell membrane against a gradient).

• This constant movement of molecules is necessary to maintain Homeostasis (the stable internal state required for the cell to stay alive).

• Organisms with Mitochondria that function most efficiently in their specific environment have higher fitness, meaning Natural Selection will favor them over time.

lets link Cell Wall, Osmosis, Vacuoles, Homeostasis, and Glucose.

• Through Photosynthesis, a plant cell creates Glucose for energy.

• The cell stores excess nutrients and water in its large central Vacuole.

• To maintain Homeostasis, the cell uses Osmosis to move water into the vacuole, creating internal pressure.

• Because the plant has a rigid Cell Wall, this internal water pressure makes the cell firm (turgid) rather than causing it to burst.

• This structural integrity allows the plant to stand upright and continue reaching for the sun.

macroevolutionary change occur:

Pace of Change: Gradualism (slow/steady) vs. Punctuated Equilibrium (bursts of change because of enviromental change).

what is extinction

the end of a lineage to be extinct

extinction may occur

1) gradually or sporadically

2) naturally or created by humans

What is a typical cell made of

cytoplasm, organelles, nucleus, cell membrane

cell membrane - outer cover

provides structure

boundary between cells and its external environment

regulated what goes in and out of the cell

phospholipids

• important component of the cell membrane

• amphipathic - heads water love, tails are hydrophobic

vesicle

mediated transport

exocytosis

moving out of cell

endocytosis

bring things in

ribosomes

little dots

help build proteins all driving chemical reactions

endoplasmic reticulum

huge folded membrane

rough and smooth types

type determined by the presence or absence of ribosomes

rough: proteins

smooth: lipids

Golgi

makes vesicles

receives, processes, packages, and ships proteins and lipids

mitochondria

convert molecules into usable energy (ATP)

vacuoles

storage and membranes

2 major cell types

prokaryotes - no nucleus or organelles, simple, small, bacteria

eukaryote - complex, nucleus and organelles, large

3 energy basic or entropy, work, energy, etc

1) All living things require energy (which allows them to do work)

2) All systems (including the environment, organisms, etc) tend to go toward entropy

3) All systems are not spontaneously exploding into chaos (entropy)

6 things about homeostasis

1 - Homeostasis is a trait; it is genetically programmed

2 - Homeostasis is optimal ( most efficient)

3 - Homeostasis had nothing to do with entropy but everything to do with energy

4 - The benefit far out way any cost

5 - maintenance homeostasis, uglina maintained a little homeostasis

6 - applies to all organisms in some manner

metabolism

The sum of all chemical activities within individuals

metabolism = catabolism + anabolism

catabolism

A process that breaks down complex molecules into simple ones

anabolism

process that synthesizes complex molecules from simple ones: - ex amino acid into proteins

If all organisms require ATP energy, where do they all get it?

photosynthesis and respiration

respiration

converts chemical energy into ATP

or

conversion of energy from chemical bonds in nutrients to ATP energy

ATOMS 2 things can happen

1) The election emits a low-energy light wave and goes back to normal - this process is fluorescence

2) the exited electron (and its energy) transfers to another atom, molecule

photosynthetic pigments

molecules that absorb light energy, transfer it to electrons, and pass it on

2 major groups of reaction

1) Light reaction - energy is captured - makes ATP

2) Dark reactions - Calvin-Benson cycle - make glucose

light reaction

• Light excites electrons, which are used to make ATP

• Oxygen is a waste product here

• The ATP will be used in a dark reaction

Dark reactions

• take energy from ATP and store it in more stable sugar molecules

Why don’t cells just directly use glucose and oxygen in one quick step to get energy

1) reaction is rapid, difficult to control

2) most energy is lost or unavailable ( heat gets lost )

aerobic respiration

has oxygen

glycolysis

The citric acid cycle

election transport chain and chemiosmosis

stages of aerobic respiration

glycolysis - outside of mitochondria

formation of acetyl coenzyme A

citric acid cycle

and ETC

glycolysis

• Splitting sugar in half - catabolic process - releasing energy

• happens without/inside mitochondria

citric acid cycle

breaking down glucose the rest of the way

• Completes the breakdown of the carbon molecules in CO2

• make some ATP

• Generates NADH

• recycles

electron transport change

• Generates ATP from NADH

• huge return of ATP

• Oxygen removes waste to maintain diffusion

aerobic respiration

• gives us a big return of ATP and loses glucose to create ATP

• Other organic molecules can also be used to generate ATP

anaerobic respiration

• without oxygen

• less efficient

• produces a toxin

active and passive transport

active - needs energy to do it - going against the concentration gradient - low to high gradient

passive - has to go through proteins

Fluid Mosaic Model

The Fluid Mosaic Model is a way to describe the cell membrane as a flexible, shifting boundary rather than a solid wall.

• "Fluid" means the individual molecules (fats called phospholipids) are not stuck in place; they slide and drift around like oil on the surface of water.

• "Mosaic" means the membrane is made of many different parts—like proteins, cholesterol, and sugars—dotted throughout the fat layer like tiles in a mosaic artwork.