Bio Unit 4 Test

Nucleus

Mayor of the cell, contains DNA.

Cytoplasm

Contains all of the organelles and provides structure; site of metabolic reactions (e.g., glycolysis).

Chromatin

DNA inside of the nucleus, composed of DNA + histone proteins; regulates gene accessibility.

Golgi Apparatus

Shipping center of the cell, modifies, sorts, and packages proteins/lipids.

Mitochondria

Powerhouse of the cell, creates ATP; involved in apoptosis.

Vacuole

Medium-sized organelles responsible for housing and taking out waste; maintains turgor pressure in plants.

Lysosome

Small organelles responsible for taking out waste; contains hydrolytic enzymes.

Centrioles

Used during cell reproduction for moving of DNA; found in animal cells.

Cell Wall

Protects the plant cell from outside; made of cellulose in plants.

Cell Membrane

Protective layer of animal cell, semi-permeable, allows selective transport.

Chloroplast

Photosynthesis center of plant cells; contains chlorophyll and its own DNA.

Endoplasmic Reticulum

Acts as roads of cell; Rough ER synthesizes secretory/membrane proteins.

Ribosome

Produce proteins; free ribosomes make cytoplasmic proteins.

Cell Transport

Cell membrane allows selective transport, only allowing some substances in.

Phospholipid Bilayer

Structure of the cell membrane with embedded proteins, cholesterol, and carbohydrate chains.

Nuclear Envelope

Double membrane with pores regulating transport around the nucleus.

Nucleolus

Where ribosomal RNA (rRNA) is synthesized within the nucleus.

Cytoskeleton

Composed of microfilaments, microtubules, and intermediate filaments for structure and movement.

Lysosomal Dysfunction

Linked to diseases such as Tay-Sachs.

Contractile Vacuoles

Found in some protists for water regulation.

Cilia/Flagella

Centrioles form the base of these structures.

Rough ER

Studded with ribosomes; synthesizes secretory/membrane proteins.

Smooth ER

Involved in lipid synthesis, detoxification, and calcium ion storage.

Gene Expression

Controlled by the nucleus, not just limited to DNA storage.

Turgor Pressure

Maintained by the central vacuole in plant cells.

Autophagy

Process by which lysosomes break down cellular debris and organelles.

Endosymbiotic Theory

Mitochondria contain their own DNA, supporting this theory.

Fluid Mosaic Model

Describes the structure of the cell membrane with a phospholipid bilayer.

Gene Accessibility

Regulated by chromatin and epigenetic modifications.

Prokaryotic

Does not contain a nucleus

Eukaryotic

Contains a nucleus

Organelle

A component of a cell -> specialized structure with a specific function

Osmosis

The diffusion of water across a semi-permeable membrane

Hypotonic

Water moves into the cell because the solute concentration is higher inside the cell than outside. Animal cells lyse; plant cells become turgid.

Isotonic

No net water movement, equally comes in and goes out

Hypertonic

Water moves out of the cell because the solute concentration is higher outside than inside. Animal cells crenate; plant cells plasmolyze.

Selective Permeability

The ability of a cell to selectively allow things through its membrane. Hydrophobic core blocks polar molecules; proteins regulate transport.

Concentration Gradient

The gradient of molecule concentration on two sides of a semipermeable membrane

Passive Transport

Transport that goes along the concentration gradient, molecules move from a high concentration to low concentration, no ATP required

Diffusion

Movement of molecules from along the concentration gradient until equilibrium

Facilitated Diffusion

Diffusion with the help of specific proteins, such as carrier or channel proteins allowing for charged and larger molecules to cross the concentration gradient. No energy needed; examples include ion channels (e.g., Na⁺) or glucose transporters.

Channel Proteins

Always passive transport, less selectivity, allows charged and big molecules to pass through, faster than other proteins. Leak channels (always open) vs. gated channels (open with signals). Mention aquaporins: Specialized for water transport.

Carrier Proteins

Passive or active, only transport specific molecules (small, uncharged), slower because of conformational changes. When used in active transport, require ATP.

Active Transport

Transport against the concentration gradient, going from low concentration to high, requires ATP

Endocytosis

Cells take in molecules from outside the cell with the help of vesicles, phagocytosis (solids), pinocytosis (liquids), receptor-mediated (targeted uptake).

Exocytosis

Cells release molecules from inside the cell with the help of vesicles

Solute

Substance dissolved in a solvent

Solution

Mixture of the solute and solvent molecules; homogenous mixture

Solvent

Substance that a solute is dissolved in; dissolving medium, typically in greater quantity

Cellular Respiration

The process by which animals and plants take in oxygen and food, creating ATP for energy: C6H12O6 + 6O2 -> 6CO2 + 6H2O

Homeostasis

A state of equilibrium stable internal conditions despite external changes

Photosynthesis

The process by which plants take in carbon dioxide and water, creating glucose for energy: 6CO2 + 6H2O -> C6H12O6 + 6O2

Products

The ending molecules in a chemical reaction, effects of something acting upon the products

Reactants

Starting molecules

ATP

An energy storage chemical, containing three phosphates that provide energy

Mitochondria

The organelle in the cell responsible for making energy in animals

Chloroplast

Organelle in plant cells responsible for doing photosynthesis

Law of Conservation of Energy

States that energy can never be created or destroyed, it will just change forms.

Light dependant reactions

Step 1 of photosynthesis, requires light. Occurs in the thylakoid membrane, Inputs: Light energy, water (H₂O), NADP⁺, ADP. Outputs: ATP, NADPH, and oxygen (O₂) as a byproduct (from water splitting); Photolysis: Water is split by Photosystem II to release electrons, protons (H⁺), and oxygen.

Electron Transport Chain (ETC)

Electrons move from Photosystem II → ETC → Photosystem I → NADP⁺ reductase (producing NADPH).

Chemiosmosis

Proton gradient across the thylakoid membrane drives ATP synthesis via ATP synthase.

Light Independent Reactions (Calvin Cycle)

Step two of photosynthesis, actually converts glucose into energy fixes CO₂ to synthesize glucose (using ATP and NADPH from the light-dependent reactions). Occurs in the stroma.

Carbon Fixation

CO₂ binds to RuBP (ribulose bisphosphate) via the enzyme RuBisCO.

Reduction

ATP and NADPH convert 3-PGA into G3P (a sugar precursor).

Regeneration

RuBP is recycled to continue the cycle.

Photosystem I

Second part of the electron transport chain, reenergizes electrons with light (absorbs light at 700 nm, called P700). Transfers electrons to NADP⁺ reductase, producing NADPH.

Photosystem II

First part of electron transport chain, energizes electrons with light (electrons provided through electron carriers like NADH).

Electron Source

Water (not NADH; NADH is used in cellular respiration, not photosynthesis).

Connection to ETC

Electrons from PSII pass through the cytochrome b6f complex, creating a proton gradient.

Glycolysis

Step 1 of Cellular respiration, takes glucose molecules and turns them into 2 pyruvate and ATP, occurs in the cytoplasm.

Pyruvate Oxidation

Step 2 of Cellular respiration, takes the pyruvate molecules, CoA and NAD+ and uses the ATP to turn them into NADH, Acetyl CoA, and CO2 (Aerobic cellular respiration only).

Krebs Cycle

Step 3 of cellular respiration, takes the Acetyl CoA and a 4-C molecule and converts them into NADPH and FADH2.

Oxidative Phosphorylation

Also known as the electron transport chain, takes the NADPH and FADH2 (electron carriers), energizes them with light energy, creates a hydrogen ion gradient, moving protons through ATP synthase and energizes ADP into ATP (adding a phosphate group).

Aerobic respiration

Process by which oxygen is used to do cellular respiration.

Anaerobic respiration

Process by which oxygen isn't used to do cellular respiration, and instead fermentation occurs; only producing a total of 2 ATP.

Lactic acid fermentation

Occurs in animals, part of anaerobic respiration: Glycolysis splits glucose into 2 pyruvate molecules, producing 2 ATP and 2 NADH. Pyruvate accepts electrons from NADH, converting it into lactic acid (lactate). NAD⁺ is regenerated to keep glycolysis running. During intense exercise, muscle cells switch to lactic acid fermentation when oxygen is depleted. Lactic acid buildup causes muscle fatigue.

Alcoholic Fermentation

Occurs in plants, fungi, and bacteria, part of anaerobic respiration. Glycolysis produces 2 pyruvate, 2 ATP, and 2 NADH. Pyruvate is converted into acetaldehyde (releasing CO₂). Acetaldehyde accepts electrons from NADH, forming ethanol (alcohol). NAD⁺ is regenerated.

Examples of Alcoholic Fermentation

Bread rising (yeast produces CO₂ gas). Beer/wine production (ethanol is the alcohol).

Photosynthesis Reactants

Know which part of the plant photosynthesis occurs.

Photosynthesis Products

Be able to identify the reactants and the products for photosynthesis and cellular respiration.

Photosynthesis Equations

Be able to write the equations (word equation AND chemical equation) for the process of photosynthesis and for the process of cellular respiration.

Relation of Processes

Know how the two processes are related.

Purpose of Phases

Identify the purpose of each phase of photosynthesis and cellular respiration.

Photosynthesis Lab Activity

Be able to interpret a diagram that represents the virtual photosynthesis lab activity.

Major Molecules

Identify the major molecules in the reactions of photosynthesis and cellular respiration (NADP, NADPH, ATP, G3P, Pyruvate, etc).

Types of Respiration

Understand the various types of respiration and why they occur along with important molecules or byproducts produced.