Honors Biology

Cellular Respiration

The aerobic process where cells harvest energy from glucose to make ATP.

Autotroph

An organism that makes its own food, such as plants and algae.

Cellular Respiration

The aerobic process where cells harvest energy from glucose to make ATP.

Autotroph

An organism that makes its own food, such as plants and algae.

Heterotroph

An organism that obtains food by consuming other organisms.

Ingredients of Photosynthesis

Carbon dioxide and water.

Products of Photosynthesis

Glucose and oxygen.

Cellular Respiration Location

Occurs in mitochondria of cells.

ATP

The primary form of energy used by cells.

Aerobic

A process that requires oxygen.

Redox Reaction

A chemical reaction involving the transfer of electrons.

Oxidation

The loss of electrons from a substance.

Reduction

The gain of electrons by a substance.

Glycolysis

First stage of cellular respiration; glucose is split into two pyruvate molecules, producing two ATP and NADH.

Citric Acid Cycle

Second stage; breaks down pyruvate into carbon dioxide, forming NADH, FADH₂, and two ATP.

Electron Transport Chain

Uses electrons to create a hydrogen ion gradient, producing many ATP.

ATP Synthase

An enzyme that synthesizes ATP from ADP and phosphate.

Fermentation

Anaerobic energy process that uses only glycolysis and occurs in the cytoplasm.

Photosynthesis

Process where plants convert light energy into glucose.

Photosynthesis Equation (in words)

Carbon dioxide plus water plus light energy yields glucose and oxygen.

Chloroplast

Organelle where photosynthesis takes place.

Thylakoid

Membrane sacs in chloroplasts where light reactions happen.

Grana

Stacks of thylakoids.

Stroma

Fluid inside chloroplasts.

Stomata

Pores on leaves where carbon dioxide enters and oxygen exits.

Light Reactions

Convert light energy into chemical energy (ATP and NADPH).

Calvin Cycle

Uses ATP and NADPH to make glucose from carbon dioxide.

Chlorophyll a

Main pigment that absorbs blue-violet and red light.

Chlorophyll b

Accessory pigment that expands light absorption range.

Carotenoids

Accessory pigments that absorb different wavelengths and protect chlorophyll.

Cell Division

Process by which a parent cell divides into daughter cells.

Asexual Reproduction

Produces identical offspring from one parent without gametes.

Sexual Reproduction

Combines sperm and egg to form genetically unique offspring.

Mitosis

Division that results in two identical diploid cells.

Meiosis

Division that results in four unique haploid cells.

Binary Fission

Asexual division in prokaryotes.

Chromatin

DNA and protein complex found in the nucleus.

Sister Chromatids

Identical copies of a chromosome attached at the centromere.

Centromere

Point where sister chromatids are joined.

Interphase

Cell growth and DNA replication phase; includes G1, S, and G2.

Mitotic Phase

Includes mitosis (nuclear division) and cytokinesis (cytoplasm division).

Cytokinesis in Animals

Involves formation of a cleavage furrow.

Cytokinesis in Plants

Involves formation of a cell plate that becomes the cell wall.

Cancer

Disease of uncontrolled cell division.

Benign Tumor

Non-spreading, localized cell growth.

Malignant Tumor

Cancerous and can spread (metastasize).

Radiation Therapy

Destroys cancer cells by damaging DNA.

Chemotherapy

Uses drugs to stop cell division in cancer cells.

Homologous Chromosomes

Chromosome pairs with same genes but possibly different alleles.

Diploid

A cell with two sets of chromosomes (one from each parent).

Haploid

A cell with one set of chromosomes (gametes).

Crossing Over

Exchange of genetic material between homologous chromosomes during meiosis I.

Independent Assortment

Random alignment of chromosome pairs during metaphase I.

Nondisjunction

Failure of chromosomes to separate during meiosis, leading to abnormal chromosome numbers.

Down Syndrome

Genetic disorder caused by an extra copy of chromosome 21 (Trisomy 21).

Genetics

Study of heredity and inheritance.

Mendel

Monk who discovered the basic laws of inheritance using pea plants.

Gene

A unit of heredity that codes for a trait.

Allele

Different forms of a gene.

Homozygous

Two identical alleles for a trait.

Heterozygous

Two different alleles for a trait.

Dominant Allele

Expressed when present.

Recessive Allele

Only expressed when dominant allele is absent.

Phenotype

Physical expression of a trait.

Genotype

Genetic makeup of an organism.

Punnett Square

Diagram used to predict genotype and phenotype combinations.

Law of Segregation

Allele pairs separate during gamete formation.

Law of Independent Assortment

Alleles of different genes sort independently during gamete formation.

Testcross

Cross between unknown genotype and homozygous recessive to determine unknown.

Pedigree

Diagram showing inheritance of traits in a family.

Carrier

A person who has a recessive allele but does not show the trait.

Incomplete Dominance

Heterozygote has an intermediate phenotype (e.g., red and white make pink).

Codominance

Both alleles are fully expressed in heterozygotes (e.g., AB blood type).

Pleiotropy

One gene affects multiple traits.

Polygenic Inheritance

Traits controlled by more than one gene (e.g., skin color, height).

Linked Genes

Genes located close together on a chromosome and inherited together.

DNA

Molecule storing genetic instructions; made of nucleotides.

Nucleotide

DNA building block: phosphate, sugar, and nitrogen base.

Nitrogen Bases in DNA

Adenine, Thymine, Cytosine, Guanine.

RNA Nitrogen Bases

Adenine, Uracil, Cytosine, Guanine.

Double Helix

Twisted ladder shape of DNA discovered by Watson and Crick.

DNA Replication

The process of copying DNA before cell division.

Semiconservative Replication

Each new DNA has one original strand and one new strand.

Transcription

DNA is used to make messenger RNA (mRNA).

Translation

mRNA is used to build proteins.

RNA Polymerase

Enzyme that makes RNA from DNA template.

tRNA

Transfers amino acids to ribosomes during translation.

Ribosome

Site where proteins are synthesized.

Codon

Three-base mRNA sequence coding for one amino acid.

Mutation

Any change in the DNA sequence.

Silent Mutation

Does not affect protein sequence.

Missense Mutation

Changes one amino acid in the protein.

Nonsense Mutation

Creates a stop codon and shortens the protein.

Frameshift Mutation

Insertion or deletion that alters reading frame.

Virus

Non-living infectious agent made of genetic material and protein coat.

Capsid

Protein shell of a virus.

Bacteriophage

Virus that infects bacteria.

Lytic Cycle

Virus replicates and destroys host cell.

Lysogenic Cycle

Viral DNA integrates into host DNA and replicates with it.

Gene Regulation

Turning genes on or off.

Gene Expression

Process of transcribing and translating a gene into a protein.

Repressor Protein

Blocks transcription by binding to DNA.