Biology 400 Semester 2 Review: Cellular Respiration & Genetics

Cellular Respiration

Oxidizes fuel molecules and generates ATP for cellular work.

Photosynthesis

Converts light energy into chemical energy stored in glucose.

Glycolysis

The first step of cellular respiration where glucose is split into two molecules of pyruvate.

Krebs Cycle

The second step of cellular respiration where pyruvate is further broken down, releasing energy stored in high-energy electrons.

Electron Transport Chain (ETC)

A series of proteins embedded in the inner mitochondrial membrane that use electrons to create a proton gradient for ATP synthesis.

Overall Chemical Equation for Cellular Respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

Kilocalorie

A unit of energy used to measure the energy content of foods and beverages; equivalent to 1 calorie in food context.

Energy Release from Glucose

Glucose is broken down through glycolysis, the Krebs cycle, and the electron transport chain, releasing energy.

Redox Reactions in Cellular Respiration

Transport electrons; reduction reactions gain electrons while oxidation reactions lose electrons.

Role of NADH

An electron carrier produced during glycolysis and the citric acid cycle that carries high-energy electrons to the electron transport chain.

Role of Oxygen in Cellular Respiration

Acts as the final electron acceptor in the electron transport chain, combining with electrons and protons to form water.

Stages of Cellular Respiration

Glycolysis, pyruvate oxidation and the citric acid cycle, and oxidative phosphorylation.

Breathing and Cellular Respiration

Breathing in O2 is an input and breathing out CO2 is an output of cellular respiration.

ATP Usage in the Human Body

Used for muscle contraction, active transport, molecule synthesis, cell growth, nerve signaling, heat production, detoxification, and cellular function.

Cellular Regions of Glycolysis

Occurs in the cytoplasm.

Cellular Regions of the Citric Acid Cycle

Occurs in the mitochondrial matrix.

Cellular Regions of Oxidative Phosphorylation

Occurs in the inner mitochondrial membrane.

Citric Acid Cycle

A stage of cellular respiration that processes Acetyl CoA and produces CO2, 3 NADH, 3 H+, FADH2, and ATP.

Oxidative Phosphorylation/ETC

The final stage of cellular respiration that uses 10 NADH, 2 FADH2, ADP, P, and 6 O2 to yield 34 ATP and H2O.

Total Yield of ATP

The total yield of ATP molecules per glucose is about 34, but this number is not exact due to differences in cell type and mitochondrial efficiency.

Fermentation

A process that regenerates NAD+, allowing glycolysis and ATP production to continue without oxygen.

Alcoholic Fermentation

A type of fermentation that converts 2 pyruvate into 2 ethanol and 2 CO2, yielding 2 NAD+.

Lactic Acid Fermentation

A type of fermentation that converts 2 pyruvate into 2 lactic acid, yielding 2 NAD+.

Evolutionary History of Glycolysis

Glycolysis is one of the oldest metabolic pathways, likely originating in early unicellular organisms around 3.5 to 4 billion years ago.

Carbohydrates as Fuel

Carbohydrates, such as sucrose and starch, are primary sources of calories for cellular respiration.

Fats as Fuel

A gram of fat yields more ATP than starch or protein because it contains more high-energy bonds and generates more reducing equivalents.

Proteins as Fuel

Proteins can be used as fuel for cellular respiration, but carbohydrates and fats are more efficient sources of energy.

Biosynthesis

The process by which cells create complex molecules needed for building themselves using nutrients from food.

Raw Materials in Biosynthesis

Some food provides building blocks for new molecules, such as amino acids from proteins used to build new proteins.

Metabolic Pathways

Cells use pathways like glycolysis and the citric acid cycle to convert nutrients into different types of molecules.

Energy Use in Biosynthesis

Biosynthesis requires energy, which is supplied by ATP, the energy currency of the cell.

Regulation of Biosynthesis

The biosynthesis process is carefully controlled by feedback mechanisms to ensure cells produce only what they need.

Acetyl-CoA

Created during glycolysis, it is involved in pyruvate oxidation between steps 1 and 2 of cellular respiration.

alcohol fermentation

in bacteria and yeast that turns pyruvate into ethanol and CO2

intermediates

something in between two steps, like the phosphate being added and broken down during glycolysis

ATP synthase

the enzyme that uses passive transport and the H+ gradient to produce ATP in the ETC

kilocalorie (kcal)

a unit of energy used to measure the energy content of foods and beverages

chemiosmosis

energy from P+ gradient to make ATP

NAD+

uncharged electron carrier

oxidation

when a substance loses electrons

oxidative phosphorylation

ETC

redox reaction

OIL RIG

electron transport chain

uses NADH and FADH2 to actively pump H+ ions into the intermembrane space, then ATP synthase harvests the gradient to make ATP.

reduction

when a substance gains electrons

cell cycle

consists of the interphase and mitotic (M) phase.

interphase

includes the G1 phase where the cell grows, produces proteins, and performs normal functions, S phase when DNA replication occurs, doubling the genetic material, and G2 phase where the cell prepares for mitosis by producing necessary proteins and organelles.

Mitotic Phase

cell division consists of Mitosis (Division of the nucleus with PMAT) and Cytokinesis (Division of the cytoplasm).

role of the cell cycle

essential for growth and development, tissue repair and regeneration, reproduction, and maintaining genetic stability.

genes code for proteins

through transcription and translation.

transcription

RNA polymerase reads a gene's DNA sequence and synthesizes a complementary messenger RNA (mRNA).

translation

the mRNA travels to the ribosome, where transfer RNA (tRNA) brings amino acids that match the mRNA codons.

sister chromatids

are connected next to each other with the centromere and separate from each other during cell division.

cell division

is essential for prokaryotic and eukaryotic life because it transmits specific genetic info at the cellular level to each species in order to create more members.

binary fission

is when prokaryotic cells divide in half, duplicating their chromosomes, elongating, and dividing into two identical daughter cells.

prokaryotic cell division

occurs through binary fission, a simple and fast process.

eukaryotic cell division

occurs through mitosis, a more complex process where multiple linear chromosomes replicate and are separated by the mitotic spindle.

checkpoints in eukaryotic division

are tightly regulated to ensure proper growth and division.

M phase

Mitotic phase that produces 2 daughter cells.

Prophase

Chromosomes condense, spindles form, nucleus breaks down.

Metaphase

When chromosomes align in center of cell.

Anaphase

When chromatids separate in mitosis.

Telophase

Chromosomes decondense and nuclear envelope reforms.

Cytokinesis

Cytoplasmic division where two new cells are formed.

Cleavage furrow

Cell indents at beginning of cytokinesis in animal cells.

Cell plate

During division in a plant, this structure forms to become new cell wall.

Centromere

Holds chromatids together.

Chromatin

DNA and proteins that make chromosomes.

Chromosome

Structure of genetic information.

Haploid

Cell that contains 1 set of chromosomes.

Diploid

Cell that contains 2 sets of chromosomes (1 from each parent).

Tumor

Abnormal growth of cells.

Benign tumor

A tumor in one spot.

Malignant tumor

Cancerous tumor that spreads through the body.

Cancer

Disease caused by uncontrolled cell division.

Metastasis

The spread of cancer cells.

Somatic cell

Body cells.

Mitosis

Process of cell division that results in two identical daughter cells.

Cell cycle control system

Set of proteins and checkpoints to regulate the cycle's progression.

Density-dependent inhibition

When cell division stops due to crowding.

Griffith's experiment

An experiment with pathogenic and nonpathogenic bacteria that suggested the existence of a material capable of transferring traits between organisms.

Hershey Chase's experiment

An experiment that confirmed DNA, not protein, as the genetic material.

DNA structure

Double stranded, contains deoxyribose sugar, bases A, T, C, G, and has a double helix shape.

RNA structure

Single stranded, contains ribose sugar, bases A, U, C, G, and has a single strand shape.

Chargaff's rule

In all 2 stranded DNA, the amount of adenine equals thymine and guanine equals cytosine.

DNA replication

The process by which DNA is copied, involving complementary strands that serve as templates, unwinding by helicase, and synthesis using RNA primers.

Eukaryotic DNA replication location

Occurs in the nucleus.

Prokaryotic DNA replication location

Occurs in the cytoplasm.

Genetic code

The set of instructions in DNA that provides the information for making polypeptides.

Polypeptides

Chains of amino acids that form proteins.

RNA polymerase

The enzyme that binds to DNA to synthesize a complementary strand of mRNA.

RNA processing

The modification of eukaryotic RNA before it leaves the nucleus, including splicing and the addition of a 5' cap and a 3' poly-A tail.

tRNA structure

The structure of tRNA is related to its function of bringing corresponding amino acids during translation.

Replication fork

The structure formed during DNA replication where the DNA is unwound.

Topoisomerase

An enzyme that stabilizes the DNA molecule during replication.

DNA polymerase

The enzyme that attaches to primers and adds free nucleotides to the growing DNA strand.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during DNA replication.

Ligase

The enzyme that binds Okazaki fragments together.

Exonucleases

Enzymes that proofread the DNA during replication.

5' to 3' direction

The orientation in which nucleotides are added during DNA and RNA synthesis.

5' cap

A modified guanine added to the 5' end of mRNA during RNA processing.