Biology Unit 2

Protein- needed for growth and repair

Amino acid- the small units that make up proteins

Catalyst- speeds up chemical reaction

Enzyme- speeds up the reactions in our body

Denatured- irversible change to enzymes by high temperatures or extreme PH'S

Active site- place on the enzyme where substrate fits

Amylase- an enzyme in saliva that breaks down starch

Protease- an enzyme that breaks down protein

Lipase- an enzyme that breaks down lipids (fats)

Hydrocholric acid- kills bacteria and dissovles bones in stomach it makes enzymes work better at PH 2

Bile- not an enzyme breaks up fats so enzymes work better

Mitosis- making identical cells for repair and growth

Chromosome- strand of DNA found in nucleus 46 human body cells 23 in human gametes

Asexual reproduction- does not involve male or female gametes offspring is identical

Clone- genetically identical

Meiosis- cell division producing gametes. half the number of chromosomes

Gametes- sex cells

Stem cells- unspecialised cells that can become any type of cell

Differentiation- becomes specialised to have a particular function

Variation- difference between organisms

DNA stucture- double helix held together by 4 bases

DNA fingerprinting- way of comparing DNA to see if they come from the same or different related people

Genes- a small section of chromosome, instructions or a code to make a certain protein that gives our characteristics e.g. pigment

Allele- a version of a particular gene

Dominant- the characteristic that will show up if present

Recessive- only shows up when there are two of this allele

Homozygous- two alleles the same e.g. TT, tt

Heterozygous- two different alleles e.g. Tt

Phenotype- the appearance of a characteristic e.g. tall,short

Genotype- which alleles are present

Polydactyly- babies are born with extra fingers or toes caused by dominant allele can be inherited by one parent who has the condition

Nucleus- controls cell, contains genetic infomation

Cell membrane- controls what enters and leaves the cell

Cytoplasm- enzymes here, chemical reactions occur here

Mitochondria- respiration occurs here

Chloroplasts- photosynthesis occurs here contains chlorophyll

Vacuole- contains cell sap

Cell wall- supports the cell

Diffusion- movement of particles from area of high concentration to low concentration passive process

Tissue- similar cells working together

Organ- several tissues working together

System- several organs working together

Xylem- carries water and mineral ions up a plant

Phloem- carries sugars around the plant

Stomach and its tissues- muscles to churn food, glands produce enzymes

Phtosynthesis- using light energy convert raw materials (co2 and water) into glucose

Chlorophyll- pigment in chlroplast that capture light energy

Starch- stored form of glucose

Chloroplasts- found in leaf cells, photosynthesis occurs here

Limiting factor- the factor in shortest supply e.g. light intensity

Cellulose- tough subtance making up cell walls

Quadrat- 4 sided grid used for sampling an area

Transect- a line that is set up accross an area for sampling

Compensation Point-  the rate of photosynthesis is the same as the rate of respiration

Eqaution for photosynthesis- carbon dioxide + water --- glucose + oxygen