bio exam 1

macromolecules

carbs

lipids

proteins

nucleic acids

carbs basic component

monosaccharides

lipids basic component

components of triglycerides

protein basic component

amino acids

nucleic acids basic component

nucleotides

carbs major functions

Dietary energy, energy storage, plant structure

lipids major functions

Long-term energy storage, hormones, membranes

proteins major functions

Enzymes, structure, storage, contraction, transport

nucleic acids major functions

Information storage, transmission of biological information

carbs examples

Glucose, fructose, starch, cellulose

lipids examples

fats, steroids

proteins examples

lactase, hemoglobin

nucleic acids examples

DNA, RNA

structure determines…

functions

monomers

small individual molecules that join together to make polymers

=building blocks

polymers

large molecule made of many monomers

=completed chain

dehydration reaction

Builds polymers from monomers

removes H₂O

Think: dehydration = build

hydrolysis

breaks polymers apart

adds H₂O

important during digestion

Think: hydro = water → water breaks it apart

carbohydrates levels

Monosaccharide → Disaccharide → Polysaccharide

lipid major roles

• Long-term energy storage

• Steroid hormones

• Cell membranes

phospholipids

important because they form biological membranes

Proteins are built from…

amino acids

Shape is critical to protein function. Changing a protein's shape can change or destroy its function.

DNA and RNA are nucleic acids made from

nucleotides

prokaryotic

bacteria + archaea

smaller

simpler

no membrane-enclosed organelles

eukaryotic

protist, plants, fungi + animals

larger

more complex

membrane enclosed organelles

plant cells have…

BOTH chloroplasts and mitochondria

nucleus

• Stores DNA.

• Surrounded by a double nuclear envelope.

• Nuclear pores selectively allow movement between nucleus and cytoplasm.

• Contains the nucleolus.

nucleolus

• Ribosome precursors are assembled here.

• The lecture specifically notes that the nucleolus is NOT an organelle

ribosomes

• Protein-synthesizing machines.

Remember the information pathway:

DNA → RNA → Protein

mRNA carries coded information out of the nucleus through nuclear pores, and ribosomes translate the message into protein.

endomembrane system

Nuclear envelope → ER → Golgi → lysosomes/vacuoles → plasma membrane

Think of this as the cell's manufacturing, processing, and distribution system.

mitochondria

cellular respiration → ATP production

chloroplasts

photosynthesis → capture light energy

cytoskeleton

Three important fibers:

• Microtubules

• Microfilaments

• Intermediate filaments

Overall functions include mechanical support, shape, and movement.

microtubules

movement of organelles and chromosomes

microfilaments

actin; contraction, motility, cell division/cytokinesis

intermediate filaments

structural support

phospholipid bilayer

Can move laterally, contributing to membrane fluidity.

plasma membrane's major component is

a double layer of phospholipids

hydrophillic heads

face the watery environments inside and outside the cell

Hydrophobic tails

point inward, away from water

fluid mosaic model

Fluid = phospholipids move.

Mosaic = many different proteins are embedded in the membrane

Unsaturated fatty-acid tails contain kinks, preventing tight packing and making the membrane more fluid. Cholesterol also influences membrane fluidity.

do Hydrophobic/nonpolar molecules cross?

yes, they cross relatively easily.

do Hydrophilic molecules, ions and polar molecules cross?

no, they do NOT cross easily and often require proteins.

6 functions of membrane proteins

• Transport

• Enzymatic activity

• Signal transduction

• Cell-cell recognition

• Intercellular joining

• Attachment to cytoskeleton & ECM

passive transport

• Does NOT require ATP.

• Moves substances down their concentration gradient.

Includes:

• Diffusion

• Facilitated diffusion through channels/carriers

active transport

• Requires energy (ATP).

• Moves substances against their concentration gradient.

sodium-potassium pump

Very testable:

3 Na⁺ OUT / 2 K⁺ IN

Requires ATP and maintains Na⁺ and K⁺ concentration gradients.

bulk transport

Large molecules cross membranes using vesicles and energy.

exocytosis

=EXIT

• Vesicle fuses with membrane.

• Contents released outside cell.

endocytosis

=ENTER

cell brings material inside

3 types of bulk transport

• Phagocytosis = "cell eating"

• Pinocytosis = "cell drinking"

• Receptor-mediated endocytosis = selective uptake using receptors

cellular respiration

Cellular respiration extracts energy from glucose to produce ATP.

1. Glycolysis → 2. Pyruvate oxidation + Citric Acid Cycle → 3. Oxidative phosphorylation

exergonic

most ATP comes from…

oxidative phosphorylation

ATP production

2 mechanisms:

Substrate-level phosphorylation (SLP)
→ phosphate is transferred directly to ADP.

Oxidative phosphorylation (OP)
→ uses electrons from NADH/FADH₂ and the ETC.

32 ATP/glucose

• 4 from SLP

• 28 from OP

stage 1 glycolysis

📍 Location: cytosol

Energy:

• Uses 2 ATP

• Produces 4 ATP

• NET = 2 ATP

• Produces 2 NADH

Glycolysis can occur with or without oxygen.

:Glyco = glucose
lysis = split

splitting sugar.

pyruvate oxidation

Pyruvate is converted into acetyl-CoA, which enters the citric acid cycle

Key products per glucose:

• 2 acetyl-CoA

• 2 NADH

• 2 CO₂

stage 2 citric acid cycle

also called : krebs cycle, TCA cycle

Per glucose / 2 turns:

4 CO₂ + 2 ATP + 6 NADH + 2 FADH₂

NADH and FADH₂ carry high-energy electrons to the ETC.

stage 3 oxidative phosphorylation

largest ATP payoff

NADH/FADH₂ → ETC → H⁺ gradient → ATP synthase → ATP

Electrons move down the ETC and eventually reach O₂, forming water.

The ETC establishes an H⁺ gradient.

Then:

H⁺ flows through ATP synthase → ATP is produced.

chemiosmosis

H⁺ flows through ATP synthase → ATP is produced.

photosynthesis

6 CO₂ + 6 H₂O + solar energy → C₆H₁₂O₆ + 6 O₂

Overall reverse chemical change of cellular respiration

endergonic

chloroplast structure

thylakoids

stroma

thylakoids

membranous sacs

contain chlorophyll

can stack into grana

stroma

fluid surrounding the thylakoids

light reactions

in the thylakois

Inputs involve:
Light + H₂O + NADP⁺ + ADP

Major products:

O₂ + ATP + NADPH

Water is split, O₂ is released, NADP⁺ is reduced to NADPH, and ATP is generated by photophosphorylation.

photosystems

Photosystem II works FIRST

-reaction enter = P680

Photosystem I works SECOND

-reaction center= P700

linear electron flow

H₂O → PSII → ETC → PSI → NADPH

During the process:

• Water is split.

• O₂ is produced.

• Electrons travel through PSII and PSI.

• H⁺ gradient forms.

• ATP synthase produces ATP.

• NADP⁺ becomes NADPH.

Final products:

ATP + NADPH + O₂

cyclic electron flow

Uses mainly PSI

-produces ONLY ATP

• provides additional ATP when needed

calvin cycle

In the stroma

uses: CO₂ + ATP + NADPH

to build carbohydrates.

Carbon enters as CO₂ and leaves the cycle as G3P. The cycle regenerates its starting molecule, RuBP.

3 phases of calvin cycle

carbon fixation, reduction, regeneration

carbon fixation (calvin cycle)

• CO₂ is incorporated.

• Enzyme = Rubisco.

reduction (calvin cycle)

• ATP + NADPH are used.

• G3P is formed.

regeneration (calvin cycle)

• RuBP is regenerated so the cycle can continue

cellular respiration main organelle

mitochondrion

cellular respiration main purpose

extract energy from glucose

cellular respiration overall energy

exergonic

cellular respiration major gas consumed

O₂

cellular respiration major gas produced

CO₂

cellular respiration chemiosmosis H⁺ reservoir

intermembrane space

cellular respiration H⁺ flows toward

matrix

photosynthesis main organelle

chloroplast

photosynthesis main purpose

convert solar energy to chemical energy

photosynthesis overall energy

endergonic

photosynthesis major gas consumed

CO₂

photosynthesis major gas produced

O₂

photosynthesis chemiosmosis H⁺ reservoir

thylakoid space

photosynthesis H⁺ flows toward

stroma