TRU Biol 2131 Exam Questions With Complete Solutions | Latest Update 2026 | Graded A+

TRU Biol 2131 Exam Questions With Complete Solutions | Latest Update 2026 | Graded A+ What are the 3 tenets of the cell theory? - answer-1) All organisms are composed of one or more cells 2) The cell is the structural unit of life 3) Cells can arise only by division from a pre-existing cell Fundamental properties that are shared by all cells (9)? - answer-- Cells are highly complex and organized - Possess a genetic program - Can reproduce - Acquire and use energy - Carry out chemical reactions - Engage in mechanical activities - Respond to stimuli - Capable of self-regulation How is energy passed from one organism to the next? - answer-Light energy is converted by photosynthesis into chemical energy that is stored in energy-rich carbohydrates. These carbs are source of energy for animal cells. Common features between PROK and EUK (9) - answer-PM, genetic info (DNA), similar mechanisms for transcription/translation, shared metabolic pathways (glycolysis, TCA), ATP, photosynthesis mechanisms, protein synthesis, proteasomes, cytoskeletal filaments built of proteins similar to actin and tubulinEUK only features - answer-nucleus, complex chromosomes (DNA + histones), cytoplasmic organelles, complex cytoskeletal system/flagella/cilia, phagocytosis, diploidy, sexual reproduction, mitotic spindles two domains of PROK cells - answer-archae and bacteria (archae are more closely related to EUK) EUK specialized cells are formed by - answer-differentiation As cell size increases, surface area/volume ratio ___ - answer-decreases Surface area/volume ratio importance in cell size. - answer-Larger the cell (cytoplasmic volume) = longer it takes to move things in/out, generate messages required by cell - Too big = SA not sufficient to support cell activities viruses - obligatory intracellular parasites - answer-means they cannot produce unless present within a host cell are viruses considered living organisms? - answer-no; inability to reproduce/metabolize without host cells Evolutionary importance of common properties between PROK and EUK? - answer-The similarities reflect the fact that EUK cells have evolved almost certainly from PROK ancestors. Due to their common ancestry, the two types of cells share an identical genetic code that uses DNA and RNA, a common set of metabolic pathways, and many common structural features. Lytic infections - answer-- Use host cell machinery to make new virions- Will lyse host to release progeny to infect other cells lysogenic infections - answer-- Virus integrates DNA into host cell (provirus) - No lysing of host - Effects depend on type of virus viroid - answer-infectious agent consisting of a small circular RNA molecule that lacks a protein coat. Thought to cause disease by interfering with the cell's normal path of gene expression Can viruses be treated with antibiotics? - answer-No Most sugars have the general formula - answer-Ch2O carbs can be joined together by covalent ___bonds - answer-glycosidic oligosaccharides - role? - answer-small chains often found covalently attached to lipids and proteins, converting them into glycolipids and glycoproteins. - 15 glucose or fewer per chain - Role in mediating the interactions of a cell with its environment and sorting of membrane proteins to different cellular compartments glycogen - answer-- highly branched, energy storages. - Glucose polymer - animal cells starch - answer-helical arrangement, energy storage. Glucose polymer- Amylose (unbranched) vs amylopectin (branched) - Stored as densely packed granules enclosed in membrane bound organelles (plastids) within the plant cell Cellulose - answer-unbranched, highly extended, structural role. Main component in plant cell walls Chitin - answer-a polysaccharide that makes up the exoskeleton of insects and the cell walls of fungi - does not consist of glucose monomers hydrogenation of fat - answer-converts some cis bonds to trans = straighter steroid structure - answer-characteristic 4-ringed hydrocarbon skeleton Important steroid in body - answer-cholesterol - component of animal cell membranes, precursor for steroid hormones such as testosterone progesterone and estrogen phospholipid structure - answer-2FAs + glycerol one hydrophobic and one hydrophilic end function primarily in cell membranes 4 types of macromolecules? Which monomers are the building blocks of polymers? - answer-- sugars = polysaccharides - amino acids = proteins - nucleotides = nucleic acids - FAs = lipids3 polysaccharides composed of glucose polymers - answer-glycogen, starch, cellulose 3 types of lipid molecules and role of each - answer-- Fats = rich in chemical energy; energy storage - Steroids = components of animal cell membranes and precursors of steroid hormones; cholesterol is involved in membrane fluidity - Phospholipids: cell membranes functions of proteins? - answer-enzymes, structural cables, hormones/growth factors, membrane receptors/transporters, contractile filaments, antibodies, etc how are peptide bonds formed? broken? - answer-condensation (dehydration) reaction... hydrolysis 3 unique Amino Acids - answer-- Glycine: only H atom as side chain = very flexible - Proline: amino group as part of ring = produces kinks or hinges - Cysteine: contains sulfhydryl group = can form disulfide bridges Primary structure of protein - answer-linear sequence of amino acids secondary structure of protein - answer-conformation of portions of the polypeptide chain. - Alpha helix and beta sheets - Both stabilized by hydrogen bonds tertiary structure - answer-conformation of the entire polypeptide