BRAMPTON ANKI EXAM QUESTIONS Flashcards

Question

Describe how lactose is formed and where in the cell it would be attached to a polypeptide to form a glycoprotein [4 marks]

Answer 1

1) Glucose and galactose 2) Joined by condensation 3) Joined by glycosidic bonds 4) Added to polypeptide in GOLGI apparatus

Answer 2

> DNA ⟶ deoxyribose sugar > RNA ⟶ ribose sugar > DNA ⟶ contains thymine > RNA ⟶ contains uracil > DNA ⟶ long polymer chain > RNA ⟶ short polymer chain > DNA ⟶ 2 helical strands > RNA ⟶ single strand

Answer 3

From LEFT to RIGHT... Rectangle = adenine Pentagon = ribose sugar 3 circles = phosphate groups

Answer 4

1) Hydrogen bonds between the base pairs holds 2 strands together 2) Many hydrogen bonds provide strength

Answer 5

1) Cut 5 equal sized pieces of beetroot using a scalpel 2) Rinse to remove pigment on the surface after cutting 3) Add each piece to a test tube with 5 cm3 of water 4) Place each in a different temperature water bath (10, 20, 30, 40 and 50 ºC) for the same amount of time 5) Remove the beetroot so only coloured liquid is left 6) Determine the absorption of the coloured solution left using a colorimeter 7) High absorbance means more pigment was released 8) Plot on a graph, or connect the colorimeter to a computer

Answer 6

1. Growth / increase in cell number; 2. Replace cells / repair tissue / organs / body; 3. Genetically identical cells; 4. Asexual reproduction / cloning;

Answer 7

ADVANTAGES = > Best magnification and resolution > Allows internal structures to be seen DISADVANTAGES = > Can't look at living cells → specimen need to be in a vacuum > Specimen must be very thin > Artefacts present > Long preparation time and complex staining process > Doesn't form a colour image > Only 2D images produced

Answer 8

1) Phospholipid bilayer forms a barrier (to water soluble substances) 2) Fluid ⟶ can bend to take up different shapes E.G. to form vesicles / self repair 3) Channel proteins ⟶ let water soluble/charged particles substances through 4) Carrier proteins ⟶ allow for facilitated diffusion 5) Surface proteins / Glycoproteins ⟶ act as receptors 6) Cholesterol ⟶ regulates fluidity

Answer 9

1) Carrier / Channel Protein 2) Protein's are specific to substance 3) Substance moves down the concentration gradient

Answer 10

1) Sodium ions actively transported from the ileum cell to blood ` 2) This maintains the concentration gradient for sodium to enter from gut, each coupled with a glucose molecule 3) Glucose enters by facilitated diffusion via a co-transport protein with sodium ions

Answer 11

1) No ATP produced 2) Sodium ions not moved out of the cell 3) No concentration gradient for sodium to move into the cell with amino acids, hence no amino acids are absorbed

Answer 12

> Binary fission > Replication of circular DNA > Division of cytoplasm to produce 2 daughter cells > Each with a single copy of circular DNA

Answer 13

> Holds chromatids together > Attaches chromatids to spindle > Allows chromatids to move to opposite poles

Answer 14

> Growth in cell number > Replace cells > Genetically identical cells > Asexual reproduction

Answer 15

FOREIGN protein; that STIMULATES an immune response

Answer 16

> Proteins on cell surface membrane of cancer cells; > different from healthy cells (abnormal); > abnormal cell surface proteins are non-self antigens; > immunotherapy facilitates immune system by detecting non-self-proteins; > immune system mounts immune response; destroys cancer cells

Answer 17

Cell cycle describes the formation of new cells from old cells Checkpoints regulate the progression of the cell replication Genes control these checkpoints Mutation of genes Control is lost Cancer develops / uncontrolled cell cycle/mitosis

Answer 18

1) Antibody has a variable region with a specific amino acid sequence / primary structure; 2) The shape of tertiary structure of the binding site; 3) Complementary to the antigens; 4) Forms complex between antigen and antibody;

Answer 19

1) Electron microscope has a greater resolving power / objects closer together can be distinguished 2) electron (beams) have a shorter wavelength;

Answer 20

> Act as recognition sites > Help cells attach to one another + form tissues

Answer 21

> Membrane-bound vesicles found in the cytoplasm that contain a hydrolytic enzyme called lysozyme. > They are responsible for digesting invading cells / breaking down work out components

Answer 22

1) Small, flattened structure found within plant and algae cells 2) Contains a double membrane 3) Stroma is an aqueous liquid found within these membranes (contains enzymes) 4) Contains structures within called thylakoids 5) Stacked thylakoids = grana 6) Grana linked to each other by thin, flat piece of membrane called a lamellae 7) Contains circular DNA and ribosomes

Answer 23

e- beam is directed from above e- beams are scattered which are analysed by a computer to build a 3-D image.

Answer 24

1) Filter 2) Dry precipitate 3) Find mass / weight

Answer 25

1.Antibodies with the same tertiary structure 2. produced from identical plasma cells

Answer 26

e- gun produces a beam of e- -> focused on specimen by electromagnet. beam passes through specimen, denser areas are absorbed causing dark spots.

Answer 27

Mesosomes These are in foldings of the cell membrane that provide a large surface area for the attachment of the enzymes involved in respiration.

Answer 28

1) Start by pipetting a small drop of water onto the slide 2) Use tweezers to place a thin section on top of the water drop 3) Add a drop of stain E.G. eosin to make cytoplasm show up 4) Use a mounted needle to add a cover slip to protect the specimen. Try and avoid air bubbles.

Answer 29

Cholestrol regulates the fluidity of the cell-surface membrane. Key Functions: - reduces lateral movement of other molecules including phospholipids - makes the membrane less fluid at high temperatures - prevent leakage of water and dissolved ions from the cell as it is hydrophobic

Answer 30

Fungal cells are like plant cells, except: > Cell walls are made of chitin, instead of cellulose > They don’t have chloroplasts

Answer 31

A cellulose cell wall A vacuole full of cell sap Chloroplasts

Answer 32

STRUCTURE = > Oval shaped > Double membrane > Inner membranes are folded to form cristae > Has a matrix inside - this contains enzymes involved in respiration FUNCTION = > Site of aerobic respiration > ATP produced here > Found in large numbers in active cells that have high energy requirements

Answer 33

> A group of fluid-filled membrane bound flattened sacs > Processes and packages new lipids and proteins > Makes lysosomes

Answer 34

A small fluid filled sac Surrounded by a membrane Made by the Golgi apparatus Stores lipids and proteins that are made by the Golgi apparatus Transports them out of the cell by the cell surface membrane during exocytosis

Answer 35

> Site for protein synthesis > Floats free in the cytoplasm or attached to the rough endoplasmic reticulum > Made of proteins and rRNA

Answer 36

Network of fluid-filled membranes Produces and processes lipids

Answer 37

1) Rigid cellulose structure that surrounds plants 2) Provides structural support to the plant and therefore keeps it rigid

Answer 38

An organelle found enclosed by a membrane (tonoplast) In the cytoplasm of plant cells Contains sap - a weak solution of salts and sugar Helps maintain cell pressure, ensuring the cell remains rigid and prevents wilting of the plant Isolates and detoxifies unwanted chemicals in the cell

Answer 39

If the cell used lots of energy

Answer 40

This increases the surface area for absorption e.g. in the epithelial cells of the small intestine

Answer 41

A group of (specialised) cells that works together to carry out a specific function

Answer 42

Groups of different tissue that work together to perform certain functions

Answer 43

A group of organs that works together to perform a function in a multicellular organism

Answer 44

> Retains the structure of the cell, prevents it from changing shape > Made of murein polymer Murein is a glycoprotein

Answer 45

> Small loops of DNA > Contain antibiotic resistance genes amongst others Some have several plasmids, others have no plasmids

Answer 46

1) No nucleus is present 2) DNA is free in the cytoplasm 3) Circular DNA 4) Not attached to any histone proteins

Answer 47

No plasma membrane No ribosomes No cytoplasm

Answer 48

By binary fission Cells split to make two daughter cells

Answer 49

How much bigger the image is than the actual sample/specimen Magnification = size of image / size of object

Answer 50

How well can a microscope distinguish between two points that are close together

Answer 51

> SEMs can be used on thick specimens, TEMs can only be used on thin specimens > SEMs give lower resolution images than TEMs > SEMs produce 3D images

Answer 52

The separation of organelles from the rest of the cell, before examining them under an electron microscope

Answer 53

Homogenisation - Breaking cells Filtration - Removing large debris Ultracentrifugation - Separating the organelles

Answer 54

1) Bacterial is much smaller than human 2) Bacterial has cell wall but human doesn't 3) Bacterial lacks nucleus but human has nucleus 4) Bacterial lacks membrane-bound organelles but human has membrane-bound organelles 5) Bacterial have 70S ribosomes whereas human have 80S ribosomes 6) Bacterial DNA is circular but human DNA is linear 7) Bacterial DNA is 'naked' whereas human DNA is bound to histones

Answer 55

1) Cell homogenisation to break cells open 2) Filter to remove large debris 3) Use isotonic solution to prevent damage to mitochondria 4) Keep cold to prevent damage by enzyme 5) Use buffer to prevent protein denaturation 6) Centrifuge at lower speed to separate nuclei 7) Re-spin supernatant at higher speed to get mitochondria in pellet at bottom

Answer 56

Eosin is used to highlight the cytoplasm Iodine contained in potassium iodide solution highlights starch grains

Answer 57

Bacterial cells have 70S ribosomes whereas human cells have 80S ribosomes

Answer 58

Electrons have a shorter wavelength.

Answer 59

1) DNA that does not code for amino acids 2) Positioned between genes

Answer 60

Active site of enzyme is not complementary; Active site is flexible & can mould around the substrate; change in enzyme allows substrate to fit and form an E-S complex

Answer 61

1. Specific Tertiary structure enzyme (means) 2. Active site is only complementary to maltose 3. Description of induced fit; 4. Enzyme is a catalyst which lowers the activation energy required for the reaction 5. By forming an enzyme-substrate complex;

Answer 62

Energy can’t be directly released from glucose Energy released from glucose makes ATP

Answer 63

The nucleotide tide base is adenine The pentose sugar is called ribose There are three phosphate groups A modified nucleotide, known as a nucleotide derivative Energy is stored in bonds between phosphate groups, and released by hydrolysis reactions

Answer 64

ATP is broken down under a hydrolysis reaction Broken down into ADP (adenine diphosphate) and Pi (inorganic phosphate) The phosphate bonds are broken, and energy is released This is catalysed by ATP hydrolase, an enzyme

Answer 65

Contain core genetic material, as RNA or DNA Have a ‘capsid’ which is a protein coat Attachment proteins stick out from the edge of the capsid to allow the virus to attach to a host cell

Answer 66

Added to another compound by phosphorylation This makes the compound more reactive

Answer 67

A condensation reaction Between ADP and Pi This occurs during respiration and photosynthesis Catalysed by ATP synthase

Answer 68

1) Releases energy in small / manageable amounts 2) Broken down in a one step reaction 3) Phosphorylates other compounds to make them more reactive 4) Reformed / remade / easily resynthesised

Answer 69

ADP + Pi → ATP

Answer 70

ATP cannot be stored it is an immediate source of energy Only a small amount of energy is released at a time

Answer 71

From ADP and Pi By ATP synthase During respiration/photosynthesis

Answer 72

The unstable bonds between the phosphate molecules