Back to AI Flashcard MakerBiology /LGS A-Level OCR Biology - Unit 6 - Genetics of living systems Part 4

LGS A-Level OCR Biology - Unit 6 - Genetics of living systems Part 4

Biology21 CardsCreated about 1 month ago

This deck include promoter, terminator, and operator regions that control when and how genes are transcribed.

Lac o

Operator region of control site

Repressor protein binds here

When lactose is present causes a conformational change in repressor protein allowing it to bind to lactose instead

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Key Terms

Term
Definition

Lac o

Operator region of control site

Repressor protein binds here

When lactose is present causes a conformational change in repressor protei...

Lac z

Structural gene codes for beta galactoside

Lac y

Structural gene that codes for lactose permease

Lac operon

Inducible operon (only occurs when lactose is present from diffusion through lactose channels )

Example of transcriptional regulation

G...

Mechanism of apoptosis

Cytoskeleton broken down by enzymes, loses function

Cell shrinks and the membrane blebs, chromatin condenses

Lysosomes release enzymes ...

Uses of apoptosis

Morphogenesis - eliminating excess cells (webbed fingers)

Selection - eliminates non functional cells

Immunity - T killer eliminates da...

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TermDefinition

Lac o

Operator region of control site

Repressor protein binds here

When lactose is present causes a conformational change in repressor protein allowing it to bind to lactose instead

Lac z

Structural gene codes for beta galactoside

Lac y

Structural gene that codes for lactose permease

Lac operon

Inducible operon (only occurs when lactose is present from diffusion through lactose channels )

Example of transcriptional regulation

Group of 3 genes involved in metabolism of lactose

Mechanism of apoptosis

Cytoskeleton broken down by enzymes, loses function

Cell shrinks and the membrane blebs, chromatin condenses

Lysosomes release enzymes which break down cell components

Cell breaks up into membrane-bound fragments

Cell fragments are ingested and digested by phagocytic cells

Uses of apoptosis

Morphogenesis - eliminating excess cells (webbed fingers)

Selection - eliminates non functional cells

Immunity - T killer eliminates dangerous cells (cancer)

Organ size - eliminates excess cells

Tissue remodelling - eliminates cells no longer need (breastfeeding)

Somatic cell

Body cell

Germ line cells

Gametes

Germline mutations

Mutations in gametes so can cause genetic diseases and are passed on

Somatic mutations

Not inherited but can cause ageing and cancer

| Result of mutations in normal diploid cells

Homeobox genes

Regulatory genes that contain a homeobox sequence (180 bp)

Highly conserved in animals, plants and fungi

Regulates mitosis and apoptosis in the embryonic stage

Control body plans of an organism

Homeotic genes

Set of genes that control morphology

Homeodomain

Section of the protein coded for by the homeobox sequence (60 AA)

Hox genes

Sub type of homeobox genes

Only found in vertebrates and animals

Found in clusters on chromosomes

Controls body plans and morphology

What do Hox genes code for

A group of TF's that controls expression of structural genes associated w/ the development of an organism's appendages during its embryonic stage to form a mature body plan

What does a mutation of a Hox gene lead to

Diff body plan

What ensures features are expressed correctly

Hox genes in a Hox cluster are activated in a particular order depending on where its found on the chromosome

This matches order genes are expressed along H to T

So structural genes are activated in a carefully coordinated sequence

Why are Hox genes highly conserved

V. important

Mutations alter body plans

Mutations are selected against

Polypeptides that control the physical development of an organism

Structural proteins

Enzymes used in metabolic pathways

Hormones

Receptor proteins

Protein kinases

Activated by cyclic AMP and activate proteins through phosphorylation using ATP

siRNA

Small interfering RNA - only needed when cell has made sufficient protein

Complementary base sequence to mRNA that's to be degraded

Binds to mRNA and activates an enzyme that breaks it down

RNA nucleotides recycled to nucleus