Higher Human Biology - Unit 1 [Flashcards added using Quizlet AI]

Glucose

Sugar that is the main respiratory substrate in cells

Glycolysis

First stage in cellular respiration which occurs in the cytoplasm

Hydrogen ion

An atom of hydrogen that has lost an electron leaving a positively charged proton (symbol: H+)

Intermediate

Substance in a metabolic pathway between the original substrate and the end product

Matrix

Central cavity of a mitochondrion in which the citric acid cycle occurs

Mitochondrion

Cell organelle in which the aerobic stages of respiration occur (plural: mitochondria)

NAD

Coenzyme which carries hydrogen and electrons from glycolysis and the citric acid cycle to the electron transport chain

Net gain

Overall gain of ATP during glycolysis

Oxaloacetate

Substance that combines with the acetyl group in the citric acid cycle to form citrate

Phosphorylation

Addition of phosphate to a substance

Pyruvate

The end product of glycolysis

Fast-twitch muscle fibre

Type of muscle fibre used in short bursts of activity

Glycogen

Store of glucose in muscle cells and liver

Lactate

Produced by the fermentation of pyruvate in mammalian muscle cells

Muscle fatigue

Painful condition caused by the accumulation of lactic acid in muscles

Myoglobin

Protein in muscle tissue that can bind with oxygen

Oxygen debt

Builds up during fermentation in muscle cells

Skeletal muscle

Muscle attached to the skeleton that brings about locomotion

Slow-twitch muscle fibre

Type of muscle fibre used in endurance activities

Messenger RNA (mRNA)

carries a copy of the DNA code from nucleus to ribosome

Peptide bond

strong chemical link between amino acids in the primary structure of a polypeptide

Phenotype

outward appearance of an organism

Polypeptide

short strand of amino acids

Primary transcript

molecule made when DNA is transcribed

Ribose

sugar that forms part of an RNA nucleotide

Ribosomal RNA (rRNA)

type of RNA that makes up ribosomes

Ribosome

site of protein synthesis; composed of rRNA and protein

RNA

ribonucleic acid; several forms of single-stranded nucleic acid that are involved in protein synthesis

RNA polymerase

enzyme which unwinds and unzips DNA and adds complementary nucleotides to form a primary transcript

RNA splicing

joining of exons following the removal of introns from a primary transcript

Start codon

first codon of a messenger RNA (mRNA) transcript translated by a ribosome

Stop codon

codon within messenger RNA that signals a termination of translation into proteins

Transcription

copying of DNA sequences to make a primary transcript

Transfer RNA (tRNA)

transfers specific amino acids to the mRNA on the ribosomes

Translation

production of a polypeptide at a ribosome using information encoded in mRNA

Uracil (U)

RNA base not found in DNA; pairs with adenine in transcription and translation

Chromosome

rod-like structure that contains the genetic material of an organism encoded into DNA

Deletion (of genes)

chromosome mutation in which a sequence of genes is lost from a chromosome

Deletion (of nucleotides)

single gene mutation involving removal of a nucleotide from a sequence

Duplication

chromosome mutation in which a section of chromosome is added from its homologous partner

Frame-shift mutation

gene mutation in which all amino acids coded for after the mutation are affected

Insertion

single gene mutation in which an additional nucleotide is placed into a sequence

Inversion

chromosome mutation in which a set of genes rotates through 180°

Missense

substitution mutation; a single nucleotide change results in a codon for a different amino acid

Mutation

changes in the DNA that can result in absence of protein or synthesis of an altered protein

Nonsense

substitution mutation in which a codon is changed to a stop codon, shortening the resulting protein

Protein

large molecule made up of chains of amino acids linked by peptide bonds

Germline cell

Cell that can give rise to gametes

Haploid

Describes a cell having one set of chromosomes (e.g. gametes)

Homologous chromosomes

Matching chromosomes in a diploid cell; each member of a homologous pair has the same genes but may have different alleles

Lymphocyte

Type of white blood cell involved in a specific immune response

Meiosis

Type of cell division resulting in four haploid gametes

Mitosis

Division of the nucleus of somatic or germline cells, giving two diploid daughter cells

Multipotent stem cell

Stem cell that has the potential to make almost all cell types found within a particular tissue

Phagocyte

White blood cell that can surround, engulf and digest foreign material and pathogens

Pluripotent stem cell

Stem cell that has the potential to make almost all differentiated cell types of the body

Red blood cell

Blood cell containing haemoglobin, which can carry oxygen in the bloodstream

Regulatory signal

Molecular signal that can be received by a cell to modify its activity

Secondary tumour

Cancer formed from cells transported from a primary tumour

Somatic cell

Body cell that divides by mitosis to form more body cells

Stem cell

Unspecialised cell that can divide and then differentiate

Therapeutic

Used as part of a medical therapy

Tissue stem cells

Stem cells from tissue that divide and differentiate to become cells of that tissue

Tumour

Collection of cancer cells produced by excessive, uncontrolled cell division

Cancer cell

Cell that grows and divides in an unregulated way to produce a tumour

Differentiation

Changes to cells that allow them to specialise for different functions

Diploid

Refers to a cell having two matching sets of chromosomes

Embryonic stem cells

Stem cells from embryos that can divide and become any type of cell

Ethical issue

Issue affecting human attitudes and decisions regarding various choices

Alternative RNA splicing

Particular exons of a gene may be included within or excluded from the final, processed messenger RNA (mRNA)

Amino acid

Unit of polypeptide structure

Anticodon

Sequence of three bases on tRNA that codes for a specific amino acid

Attachment site

Site on a transfer RNA molecule to which a specific amino acid binds

Codon

Sequence of three bases on mRNA that codes for a specific amino acid

Environmental factors

Factors such as diet, light and temperature that can interact with an organism's genotype to affect its phenotype

Exon

Coding sequence of DNA

Gene

Section of DNA that codes for a protein

Gene expression

Transcription and translation of a gene to synthesise proteins

Interactions

Chemical attractions and bonding such as hydrogen bonds between amino acids, giving proteins their three-dimensional shape

Intron

Non-coding sequence of DNA

Mature transcript

RNA transcript that has been spliced and processed ready for translation

Messenger RNA (mRNA)

Carries a copy of the DNA code from nucleus to ribosome

Peptide bond

Strong chemical link between amino acids in the primary structure of a polypeptide

Phenotype

Outward appearance of an organism

Polypeptide

Short strand of amino acids

Primary transcript

Molecule made when DNA is transcribed

Ribose

Sugar that forms part of an RNA nucleotide

Ribosomal RNA (rRNA)

Type of RNA that makes up ribosomes

Ribosome

Site of protein synthesis; composed of rRNA and protein

RNA

Ribonucleic acid; several forms of single-stranded nucleic acid that are involved in protein synthesis

RNA polymerase

Enzyme which unwinds and unzips DNA and adds complementary nucleotides to form a primary transcript

RNA splicing

Joining of exons following the removal of introns from a primary transcript

Start codon

First codon of a messenger RNA (mRNA) transcript translated by a ribosome

Stop codon

Codon within messenger RNA that signals a termination of translation into proteins

Transcription

Copying of DNA sequences to make a primary transcript

Transfer RNA (tRNA)

Transfers specific amino acids to the mRNA on the ribosomes

Translation

Production of a polypeptide at a ribosome using information encoded in mRNA

Uracil (U)

RNA base not found in DNA; pairs with adenine in transcription and translation

3'-5'

Strand of nucleic acid running from a sugar to a phosphate

Adenine (A)

DNA base that pairs with thymine