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This study aims at improving students' critical thinking skills and student learning activities in biochemistry courses. The efforts in improving critical thinking skills are carried out by applying the problem-based learning model using \"blended learning\" method. Blended learning method is implemented by integrating the face-to-face learning with online learning into the syntax of problem base learning. Face-to-face learning is done in the classroom, while the form of online learning is done by utilizing internet facilities and online discussion forums. Data from observations of learning activities are also calculated using a range of values that appear and determine the criteria. The results showed that the percentage of students' critical thinking skills in the first cycle was 52.29% (quite critical), while in the second cycle it increased to 64.43% (critical). The teaching activities of lecturers in the first cycle and the second cycle were 36 (good category). Student learning activities in the first cycle is 35 (good category) and in the second cycle is 34 (good category). The conclusion of this study is the application of problem-based learning (PBL) using the blended learning method can improve critical thinking skills and student learning activities in biochemistry courses.

There are 20 200 possible amino-acid sequences for a 200-residue protein, of which the natural evolutionary process has sampled only an infinitesimal subset. De novo protein design explores the full sequence space, guided by the physical principles that underlie protein folding. Computational methodology has advanced to the point that a wide range of structures can be designed from scratch with atomic-level accuracy. Almost all protein engineering so far has involved the modification of naturally occurring proteins; it should now be possible to design new functional proteins from the ground up to tackle current challenges in biomedicine and nanotechnology.

Terahertz (THz) frequencies remain among the least utilized in the electromagnetic spectrum, largely due to the lack of powerful and compact sources. The invention of THz quantum cascade lasers (QCLs) was a major breakthrough to bridge the so-called ‘THz gap’ between semiconductor electronic and photonic sources. However, their demanding cooling requirement has confined the technology to a laboratory environment. A portable and high-power THz laser system will have a qualitative impact on applications in medical imaging, communications, quality control, security and biochemistry. Here, by adopting a design strategy that achieves a clean three-level system, we have developed THz QCLs (at ~4 THz) with a maximum operating temperature of 250 K. The high operating temperature enables portable THz systems to perform real-time imaging with a room-temperature THz camera, as well as fast spectral measurements with a room-temperature detector.GaAs-based terahertz quantum cascade lasers emitting around 4 THz are demonstrated up to 250 K without a magnetic field. To elevate the operation temperature, carrier leakage channels are reduced by carefully designing the quantum well structures.

The mechanism by which bacteria divide is not well understood. Cell division is mediated by filaments of FtsZ and FtsA (FtsAZ) that recruit septal peptidoglycan-synthesizing enzymes to the division site. To understand how these components coordinate to divide cells, we visualized their movements relative to the dynamics of cell wall synthesis during cytokinesis. We found that the division septum was built at discrete sites that moved around the division plane. FtsAZ filaments treadmilled circumferentially around the division ring and drove the motions of the peptidoglycan-synthesizing enzymes. The FtsZ treadmilling rate controlled both the rate of peptidoglycan synthesis and cell division. Thus, FtsZ treadmilling guides the progressive insertion of new cell wall by building increasingly smaller concentric rings of peptidoglycan to divide the cell.

Trees become dormant in winter, with encapsulated buds protected against harsh conditions. Tylewicz et al. found that, as the days get shorter, communication channels between cells in aspen trees shut down. The blocked plasmodesmata sequester the dormant meristems from growth signals. Growth-promoting signals can be turned on and off relatively rapidly, but the closed plasmodesmata are not so nimble. Thus, despite the occasional sunny day, the trees stay dormant until spring. Science , this issue p. 212 Aspen trees go dormant in winter because plasmodesmata, which would otherwise convey growth-promoting signals, shut down communication. In temperate and boreal ecosystems, seasonal cycles of growth and dormancy allow perennial plants to adapt to winter conditions. We show, in hybrid aspen trees, that photoperiodic regulation of dormancy is mechanistically distinct from autumnal growth cessation. Dormancy sets in when symplastic intercellular communication through plasmodesmata is blocked by a process dependent on the phytohormone abscisic acid. The communication blockage prevents growth-promoting signals from accessing the meristem. Thus, precocious growth is disallowed during dormancy. The dormant period, which supports robust survival of the aspen tree in winter, is due to loss of access to growth-promoting signals.

Photosynthesis is the natural process that converts solar photons into energy-rich products that are needed to drive the biochemistry of life. Two ultrafast processes form the basis of photosynthesis: excitation energy transfer and charge separation. Under optimal conditions, every photon that is absorbed is used by the photosynthetic organism. Fundamental quantum mechanics phenomena, including delocalization, underlie the speed, efficiency and directionality of the charge-separation process. At least four design principles are active in natural photosynthesis, and these can be applied practically to stimulate the development of bio-inspired, human-made energy conversion systems.

This Review highlights how we can build upon the relatively new and rapidly developing field of research into bacterial quorum sensing (QS). We now have a depth of knowledge about how bacteria use QS signals to communicate with each other and to coordinate their activities. In recent years there have been extraordinary advances in our understanding of the genetics, genomics, biochemistry, and signal diversity of QS. We are beginning to understand the connections between QS and bacterial sociality. This foundation places us at the beginning of a new era in which researchers will be able to work towards new medicines to treat devastating infectious diseases, and use bacteria to understand the biology of sociality. A Review of the genetics, biochemistry, ecology and evolution of bacterial quorum sensing. Bacterial communication Bacterial quorum sensing is a strategy for regulating gene expression that orchestrates collective group behaviour. In this Review, Peter Greenberg and colleagues explore the progress that has been made in understanding bacterial quorum sensing, including the genetics, biochemistry and ecology of these systems, which are used by bacteria to communicate and to coordinate their behaviour. They also discuss the future outlook for this field in terms of understanding sociality in bacteria, and how these systems could be used to develop antibacterial agents.

In the era of IR 4.0 and society 5.0 is existed the global disruptive in every aspect of human life even in the education world. This study literally stated the innovation course models in chemistry education. The innovative learning models directed to be able to develop the ability of students' use of the ICT and work together and communicate with one another in chemistry learning, especially in laboratory activities. The study of Biochemistry showed that laboratory course should be done before the theoretical course. Study of LPBSOURA in Organic Synthesis course using a retrosynthetic approach shows that students applied their concept mastery of several courses related before, green chemistry and skilful in software application in predicting target molecule. The studies also show that innovative learning models could improve students' generic science, creative and critical thinking skills, using project based learning that can increase students' thinking and skills to prepare them to face this era.

Carbohydrates are involved in nearly all aspects of biochemistry, but their complex chemical structures present long-standing practical challenges to their synthesis. In particular, stereochemical outcomes in glycosylation reactions are highly dependent on the steric and electronic properties of coupling partners; thus, carbohydrate synthesis is not easily predictable. Here we report the discovery of a macrocyclic bis-thiourea derivative that catalyzes stereospecific invertive substitution pathways of glycosyl chlorides. The utility of the catalyst is demonstrated in the synthesis of trans-1,2-, cis-1,2-, and 2-deoxy-β-glycosides. Mechanistic studies are consistent with a cooperative mechanism in which an electrophile and a nucleophile are simultaneously activated to effect a stereospecific substitution reaction.

Life builds its molecules from carbon dioxide (CO 2 ) and breaks them back down again through the intermediacy of just five metabolites, which are the universal hubs of biochemistry 1 . However, it is unclear how core biological metabolism began and why it uses the intermediates, reactions and pathways that it does. Here we describe a purely chemical reaction network promoted by ferrous iron, in which aqueous pyruvate and glyoxylate—two products of abiotic CO 2 reduction 2 – 4 —build up 9 of the 11 intermediates of the biological Krebs (or tricarboxylic acid) cycle, including all 5 universal metabolic precursors. The intermediates simultaneously break down to CO 2 in a life-like regime that resembles biological anabolism and catabolism 5 . Adding hydroxylamine 6 – 8 and metallic iron into the system produces four biological amino acids in a manner that parallels biosynthesis. The observed network overlaps substantially with the Krebs and glyoxylate cycles 9 , 10 , and may represent a prebiotic precursor to these core metabolic pathways. A chemical reaction network that overlaps with the biological Krebs and glyoxylate cycles arises from pyruvate and glyoxylate in the presence of iron, suggesting how early metabolic pathways might have arisen from CO 2 .